System and method for using resources in a communication system

ABSTRACT

In a method for using resources in a communication system, a communication region is divided into inter-sector boundary regions, sector central regions, and a sector common region, and predetermined resources are allocated to the divided regions.

TECHNICAL FIELD

The present invention relates to a multi-sector communication system,and more particularly, to a system and method for using resources thatare capable of minimizing inter-sector interference and improving useefficiency of the resources in a communication system including a cellhaving a multi-sector structure.

BACKGROUND ART

In a multi-sector communication system including a plurality of sectors,limited resources including frequency resources, code resources, andtime slot resources are divided and used among the sectors. Since thesame resources are reused by other sectors, interference can resultbetween the sectors, particularly neighboring sectors. However, althoughthe interference attributable to the reuse may cause performancedegradation, it may also increase the entire capacity of themulti-sector communication system. The interference is severe when afrequency reuse factor is 1.

Meanwhile, a next-generation communication system is being activelystudied for providing users with services with high quality of service(“QoS”), such as high transmission speed. In particular, a base station(“BS”) in the next-generation communication system divides and managesone cell into a plurality of sectors. When providing communicationservice to mobile stations (“MSs”) located in the plurality of sectors,the BS transmits data to the MSs via respective sector antennae. Here,the BS transmits the data to the MSs using beams from the sectorantennae, which overlap at a boundary between the sectors. This causesinterference between the sectors.

More specifically, the use of the sector antennae in the multi-sectorcommunication system causes inter-sector interference in a signaloverlap region between sectors, i.e., a inter-sector boundary region. Inother words, since patterns of beams from the sector antennae cannot bedesigned to be orthogonal to one another, signals from neighboringsectors overlap in the inter-sector boundary region, which causes severeinterference between the sector signals, that is, between theneighboring sectors.

A current communication system fails to avoid and minimize suchinter-sector interference, and exhibits low reuse efficiency offrequency resources when attempting to avoid and minimize theinter-sector interference. Accordingly, there is a need for a system andmethod for using resources that are capable of avoiding inter-sectorinterference in a signal overlap region between sectors by allocating acentral band orthogonal between the sectors to a inter-sector boundaryregion where signal overlap may occur, and greatly improving the reuseefficiency of frequency resource by allowing remaining frequencyresources to be reused without inter-sector interference in sectorcentral regions where there is no inter-sector interference.

Also, there is a need for a system and method capable of preventingsignal quality from being degraded by rapid reduction of antenna gain ina inter-sector boundary region that may be caused by signal transmissionor reception in the inter-sector boundary region to or from one sectorfor avoidance and minimization of inter-sector interference in theinter-sector boundary region. Also, there is a need for a system andmethod capable of providing sufficient time to perform stable dynamicchannel allocation (“DCA”) and guaranteeing stable QoS so that severalDCAs are performed at a high speed upon inter-sector handover of MSs ina plurality of sectors of a communication system. In particular, thereis a need for a system and method capable of preventing a system loadfrom increasing due to a ping-pong phenomenon upon frequency movement ina inter-sector boundary region, on a sector central boundary line, froma inter-sector boundary region to a sector central region, or from thesector central region to the inter-sector boundary region.

In other words, in the inter-sector boundary region, signal gain greatlydecreases due to rapid reduction of the antenna gain, resulting indegraded signal quality. Also, when a user moves via a sector boundaryline, signal quality degradation becomes severe. This requires rapidhandover to a neighboring sector, and accordingly, rapid DCA from acurrent sector band to another band and to a neighboring sector band.This leads to signal quality degradation and QoS degradation, and causesa ping-pong phenomenon, resulting in an increase in a system load. Thus,there is a need for a system and method for solving the problems. Thatis, there is a need for a system and method capable of avoiding andminimizing inter-sector interference in a inter-sector boundary regionof a multi-sector communication system, simplifying a handover procedurewhile maintaining signal quality, and increasing reuse efficiency of thefrequency resource.

Accordingly, the present invention allocates used bands and bands reusedin all sectors to be orthogonal among the sectors in order to avoid andminimize inter-sector interference in a inter-sector boundary region andefficiently use frequency resources. Also, there is a need for a methodand system for using resources that are capable of entirely avoiding andminimizing inter-sector interference by allocating a specific band ofeach sector to users located in a boundary region of the sector and byreusing a band allocated to be reused in all sectors where inter-sectorinterference is not considered or there is no inter-sector interference.

When an MS moves between sectors, band allocation is made based on asignal power ratio between neighboring sectors. When a user, i.e., an MSallocated a band in a current sector moves to a inter-sector boundaryregion, a BS serving the MS performs DCA to a band for the currentsector, thus avoiding and minimizing the intersector interference. Inthis case, the present invention prevents signal quality degradationcaused by rapid antenna gain reduction in the inter-sector boundaryregion in handover between sectors. In particular, the present inventionprevents signal quality degradation caused by performing rapid handoverto a neighboring sector with the intention of preventing rapid signalintensity degradation when an MS moves between sectors, i.e., performingrapid DCA to a band for a neighboring handover sector, and avoids andminimizes the inter-sector interference.

Also, movement of an MS to a neighboring sector requires DCA to a bandfor the sector, which degrades signal quality in a inter-sector boundaryregion and in turn necessitates several rapid DCAs. Accordingly, thepresent invention provides sufficient time to perform stable DCAs andguarantees QoS. Moreover, the present invention prevents a ping-pongphenomenon from being caused by frequent inter-sector handover, e.g.,frequent movement between regions in a sector, and particularly,simplifies a DCA procedure and a handover procedure in more frequent andrapid movement between sectors in a cell central region, thus reducing asystem load.

DISCLOSURE OF INVENTION Technical Problem

An object of the present invention is to provide a system and method forusing resources in a communication system.

Another object of the present invention is to provide a system andmethod for using resources in a multi-sector communication system.

Still another object of the present invention is to provide a system andmethod for transmitting and receiving signals in a multi-sectorcommunication system.

Technical Solution

According to a first aspect of the present invention, provided is amethod for using resources in a communication system, comprising thesteps of: dividing a communication region into inter-sector boundaryregions, sector central regions, and a sector common region; andallocating predetermined resources to the divided regions.

According to a second aspect of the present invention, provided is amethod for using resources in a communication system, comprising thestep of defining resources for a specific region from among resourcesavailable to the communication system, and allocating the same.

According to a third aspect of the present invention, provided is amethod for using resources in a communication system, comprising thesteps of: when a user moves between the regions of the communicationsystem, having resources allocated in each region returned; and definingresource for a region to which the user moves.

According to a fourth aspect of the present invention, provided is amethod for using resources in a communication system, comprising thesteps of: when a user moves between the regions of the communicationsystem, having resources allocated in each region returned; andallocating resources for a region to which the user moves.

According to a fifth aspect of the present invention, provided is asystem for using resources in a communication system, comprising a basestation for dividing a communication region into inter-sector boundaryregions, sector central regions, and a sector common region andallocating predetermined resources to the divided regions.

According to a sixth aspect of the present invention, provided is asystem for using resources in a communication system, comprising a basestation for defining resources for a specific region from amongresources available to the communication system, and allocating thesame.

According to a seventh aspect of the present invention, provided is asystem for using resources in a communication system, comprising a basestation for having resources currently allocated in regions of thecommunication system returned when a user moves between the regions, anddefining resource for a region to which the user moves.

According to an eighth aspect of the present invention, provided is asystem for using resources in a communication system, comprising a basestation for having resources currently allocated in regions of thecommunication system returned when a user moves between the regions, andallocating resources for a region to which the user moves.

ADVANTAGES EFFECTS

With the system and method for using resources in a communication systemaccording to the present invention, it is possible to avoid and minimizeinterference in each sector and to prevent degradation of frequencyreuse efficiency and signal quality. It is also possible to prevent anincrease in a system load by supporting stable DCA and handover. It isalso possible to increase system efficiency by efficiently managing theresources and to improve system performance by simplifying a resourceallocation procedure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 to 3 illustrate a inter-sector boundary region and a sectorcentral region in a multi-sector communication system according to anexemplary embodiment of the present invention;

FIG. 4 illustrates a scheme of dividing and defining total frequencyresources into a sector dedicated band, a inter-sector shared band, anda sector common band in a multi-sector communication system according toan exemplary embodiment of the present invention;

FIG. 5 illustrates a scheme of first dividing and defining totalfrequency resources into only a sector dedicated band and a inter-sectorshared band in a multi-sector communication system according to anexemplary embodiment of the present invention;

FIGS. 6 to 8 illustrate an example in which a BS defines a sector commonband from among a sector dedicated band or a inter-sector shared band ina multi-sector communication system according to a first rule in anexemplary embodiment of the present invention;

FIGS. 9 to 11 illustrate an example in which a BS defines a sectorcommon band from among a sector dedicated band or a inter-sector sharedband in a multi-sector communication system according to a second rulein an exemplary embodiment of the present invention;

FIGS. 12 to 14 illustrate an example in which a BS defines a sectorcommon band from among a sector dedicated band or a inter-sector sharedband in a multi-sector communication system according to a third rule inan exemplary embodiment of the present invention;

FIG. 15 illustrates a scheme of first dividing and defining totalfrequency resources into a sector dedicated band and a sector commonband in a multi-sector communication system according to an exemplaryembodiment of the present invention;

FIGS. 16 to 18 illustrate an example in which a BS defines ainter-sector shared band from among a sector dedicated band or a sectorcommon band according to the first rule in a multi-sector communicationsystem according to an exemplary embodiment of the present invention;

FIGS. 19 to 21 illustrate an example in which a BS defines ainter-sector shared band from among a sector dedicated band or a sectorcommon band according to the second rule in a multi-sector communicationsystem according to an exemplary embodiment of the present invention

FIGS. 22 to 24 illustrate an example in which a BS defines ainter-sector shared band from among a sector dedicated band or a sectorcommon band according to the third rule in a multi-sector communicationsystem according to an exemplary embodiment of the present invention;

FIG. 25 illustrates a scheme of first dividing and defining totalfrequency resources into and as only a inter-sector shared band and asector common band in a multi-sector communication system according toan exemplary embodiment of the present invention;

FIGS. 26 to 28 illustrate an example in which a BS defines a sectordedicated band from among a inter-sector shared band or a sector commonband according to the first rule in a multi-sector communication systemaccording to an exemplary embodiment of the present invention;

FIGS. 29 to 31 illustrate an example in which a BS defines a sectordedicated band from among a inter-sector shared band or a sector commonband according to the second rule in a multi-sector communication systemaccording to an exemplary embodiment of the present invention;

FIG. 32 to 34 illustrate an example in which a BS defines a sectordedicated band from among a inter-sector shared band or a sector commonband according to the third rule in a multi-sector communication systemaccording to an exemplary embodiment of the present invention;

FIGS. 35 to 38 illustrate a scheme of first defining total frequencyresources as only a sector dedicated band in a multi-sectorcommunication system according to an exemplary embodiment of the presentinvention;

FIGS. 39 to 42 illustrate a scheme of first defining total frequencyresources as only a inter-sector shared band in a multi-sectorcommunication system according to an exemplary embodiment of the presentinvention;

FIGS. 43 to 46 illustrate a scheme of first defining total frequencyresources as only a sector common band in a multi-sector communicationsystem according to an exemplary embodiment of the present invention;

FIGS. 47 to 50 illustrate a scheme in which total frequency resourcesare first not defined as any band in a multi-sector communication systemaccording to an exemplary embodiment of the present invention;

FIGS. 51 to 53 illustrate a scheme of using a inter-sector shared bandin a multi-sector communication system according to an exemplaryembodiment of the present invention;

FIGS. 54 to 56 illustrate a scheme of using a inter-sector shared bandin a 3-sector cell of a multi-sector communication system according toan exemplary embodiment of the present invention;

FIGS. 57 and 58 illustrate a scheme of using a inter-sector shared bandin a 4-sector cell of a multi-sector communication system according toan exemplary embodiment of the present invention;

FIGS. 59 to 61 illustrate a scheme of using a inter-sector shared bandin a 6-sector cell of a multi-sector communication system according toan exemplary embodiment of the present invention;

FIGS. 62 and 63 illustrate a scheme of using a inter-sector shared bandin a 3-sector cell of a multi-sector communication system according toan exemplary embodiment of the present invention;

FIGS. 64 and 65 illustrate an example in which DCA is performed when auser moves from a inter-sector boundary region to a sector centralregion in a multi-sector communication system according to an exemplaryembodiment of the present invention;

FIGS. 66 to 69 illustrate an example in which DCA is performed when auser moves from a inter-sector boundary region to a sector centralregion in a multi-sector communication system according to an exemplaryembodiment of the present invention;

FIGS. 70 and 71 illustrate an example in which DCA is performed when auser moves from a inter-sector boundary region to a sector centralregion in a multi-sector communication system according to an exemplaryembodiment of the present invention;

FIGS. 72 and 73 illustrate an example in which DCA is performed when auser moves from a inter-sector boundary region to a sector centralregion in a multi-sector communication system according to an exemplaryembodiment of the present invention;

FIGS. 74 and 75 illustrate an example in which DCA is performed when auser moves from a inter-sector boundary region to a sector centralregion in a multi-sector communication system according to an exemplaryembodiment of the present invention;

FIG. 76 to 79 illustrate an example in which DCA is performed when auser moves from a inter-sector boundary region to a sector centralregion in a multi-sector communication system according to an exemplaryembodiment of the present invention;

FIGS. 80 to 89 illustrate an example in which DCA is performed when auser moves from a sector central region to a inter-sector boundaryregion in a multi-sector communication system according to an exemplaryembodiment of the present invention;

FIGS. 90 to 97 illustrate an example in which DCA is performed when auser moves from a inter-sector boundary region to a cell central regionin a multi-sector communication system according to an exemplaryembodiment of the present invention;

FIGS. 98 to 103 illustrate an example in which DCA is performed when auser moves from a cell central region to a inter-sector boundary regionin a multi-sector communication system according to an exemplaryembodiment of the present invention;

FIGS. 104 to 110 illustrate an example in which DCA is performed when auser moves from a sector central region to a cell central region in amulti-sector communication system according to an exemplary embodimentof the present invention;

FIGS. 111 to 117 illustrate an example in which DCA is performed when auser moves from a cell central region to a sector central region in amulti-sector communication system according to an exemplary embodimentof the present invention; and

FIGS. 118 to 120 schematically illustrate an example in which resourcesare defined and used in a communication system according to an exemplaryembodiment of the present invention.

MODE FOR THE INVENTION

Hereinafter, exemplary embodiments of the present invention will bedescribed in detail. However, the present invention is not limited tothe exemplary embodiments disclosed below, but can be implemented invarious types. Therefore, the present exemplary embodiments are providedfor complete disclosure of the present invention and to fully inform thescope of the present invention to those ordinarily skilled in the art.

In embodiments of the present invention described below, a system andmethod for using resources in a communication system in which each cellincludes a plurality of sectors (“a multi-sector communication system”)are provided. Here, the multi-sector communication system is arepresentative method for increasing the number of users in acommunication system and employs cell sectorization. In the case of thecell sectorization, a base station (“MS”) uses directional antennae witha predetermined beam width, e.g., sector antennae with beam widths of120°, 90° and 60° That is, in a communication system according to anexemplary embodiment of the present invention, a BS divides one cellinto a plurality of sectors and transmits data to mobile stations (MSs)in the plurality of sectors using respective sector antennae to providecommunication services. An exemplary embodiment of the present inventionproposes a system and method for using resources for avoiding andminimizing interference between neighboring sectors caused when a BStransmits data to MSs through beams of sector antennae, particularly,when a BS transmits data to MSs by reusing all frequency resources inall sectors with a frequency reuse factor being 1.

More specifically, when sectors in one cell are theoretically orthogonalto one another, a system's capacity increases three, four and six times.However, since in actuality the sectors overlap and are not orthogonalto one another due to blunt beam patterns of the sector antenna, thesectorization does not greatly contribute to an increase in the systemcapacity. For example, an IEEE (Institute of Electrical and ElectronicsEngineers) 802.16 communication system is directed to a system structurecapable of utilizing an exact 100% of total frequency resources in onecell by allocating ⅓ of the frequency resources to each sector. In thiscase, reuse of total frequency resources in all sectors with a frequencyreuse factor being 1 may cause inter-sector interference. That is, in acommunication system using sectorized Orthogonal Frequency DivisionMultiplexing (“OFDM”), i.e., an “OFDM communication system”,interference is caused between users in a cell allocated an overlappingfrequency band. In particular, since inter-sector interference affectssystem performance more greatly than inter-cell interference, the OFDMcommunication system divides frequency resources to be orthogonal to oneanother and allocates the divided resources to sectors so that there isno interference in the cell.

Accordingly, a communication system according to an exemplary embodimentof the present invention allocates used bands and bands reused in allsectors to be orthogonal among the sectors in order to avoid andminimize inter-sector interference in a intersector boundary region andefficiently use frequency resources. Accordingly, the present inventioncan entirely avoid and minimize inter-sector interference by allocatinga specific band of each sector to users located in a boundary region ofthe sector and by reusing a band allocated to be reused in all sectorswhere inter-sector interference is not considered or there is nointer-sector interference.

When an MS moves between sectors, band allocation is made based on asignal power ratio between neighboring sectors. When a user, i.e., an MSallocated a band in a current sector, moves to a inter-sector boundaryregion, a BS serving the MS performs dynamic channel allocation (“DCA”)to a band for the current sector, thus avoiding and minimizing theinter-sector interference. In this case, a communication systemaccording to an exemplary embodiment of the present invention preventssignal quality degradation caused by rapid antenna gain reduction in theinter-sector boundary region in handover between sectors. In particular,a communication system according to an exemplary embodiment of thepresent invention prevents signal quality degradation caused byperforming rapid handover to a neighboring sector with the intention ofpreventing rapid signal intensity degradation when an MS moves betweensectors, i.e., performing rapid DCA to a band for a neighboring handoversector, and avoids and minimizes the inter-sector interference.

Also, movement of an MS to a neighboring sector requires DCA to a bandfor the sector, which degrades signal quality in a inter-sector boundaryregion and in turn requires several rapid DCAs. Accordingly, acommunication system according to an exemplary embodiment of the presentinvention provides sufficient time to perform stable DCA and guaranteesQoS. Moreover, a communication system according to an exemplaryembodiment of the present invention prevents a ping-pong phenomenon frombeing caused by frequent inter-sector handover, e.g., frequent movementbetween regions in a sector, and particularly, simplifies a DCAprocedure and a handover procedure in more frequent and rapid movementbetween sectors in a cell central region, thus reducing a system load.

Accordingly, the present invention proposes a system and method forusing resources in a multi-sector system that are capable of avoidingand minimizing inter-sector interference in a inter-sector boundaryregion, simplifying an inter-sector handover procedure, and furtherincreasing reuse efficiency of frequency resources while maintainingsignal quality even in a inter-sector boundary region. The presentinvention also proposes a system and method for using resources that arecapable of minimizing a ping-pong phenomenon caused by inter-sectorhandover or DCA and minimizing frequent DCA or inter-sector handover ina cell central region. The present invention also proposes a system andmethod for dividing total available frequency resources into a sectordedicated band, a inter-sector shared band, and a sector common band andusing the divided inter-sector shared band resources.

While an embodiment of the present invention primarily describes use offrequency resources in a central region of each sector, i.e., a sectorcentral region, a boundary region between sectors, i.e., a inter-sectorboundary region, and a sector common region, e.g., a cell centralregion, the present invention may apply to use of time resources andcode resources in regions of each sector. A scheme of defining and usingresources in a communication system according to an exemplary embodimentof the present invention will now be described in detail with referenceto FIG. 35.

FIG. 35 is a schematic diagram illustrating resource definition and usein a communication system according to an exemplary embodiment of thepresent invention. FIG. 35 a illustrates a scheme of defining and usingfrequency resources in a communication system according to an exemplaryembodiment of the present invention, FIG. 35 b illustrates a scheme ofdefining and using time resources in a communication system according toan exemplary embodiment of the present invention, and FIG. 35 cillustrates a scheme of defining and using code resources in acommunication system according to an exemplary embodiment of the presentinvention.

As shown in FIGS. 118 to 120, in the communication system according toan exemplary embodiment of the present invention, frequency resources,time resources, or code resources are defined as common resources,shared resources, and dedicated resources so that specific regions ofeach sector, e.g., a central region, a boundary region, and a commonregion, e.g., a cell central region use the resources in a communicationregion, e.g., in a communication region including at least one cell. Ascheme of defining and using frequency resources as common resources,shared resources, and dedicated resources will now be described indetail. Here, there are several schemes of dividing and defining totalavailable frequency resources, for example, into a sector dedicatedband, a inter-sector shared band, and a sector common band in acommunication system according to an exemplary embodiment of the presentinvention.

In a first definition scheme according to an exemplary embodiment of thepresent invention, a BS in a multi-sector communication system dividestotal frequency resources into a sector dedicated band, a inter-sectorshared band, and a sector common band. Frequency resources defined asthe sector dedicated band are allocated to users located in a sectorcentral region of a sector. In the other sectors in the same cell, thefrequency resources defined as the sector dedicated band are alsoallocated to users located in the sector central region of other sectorsfor reuse. Also, the BS allocates frequency resources defined as theinter-sector shared band to users located in the inter-sector boundaryregion in such a manner that the frequency resources are not used in twosectors adjacent to the inter-sector boundary region in order to avoidand minimize interference with the neighboring sectors in the cell.

In this case, the frequency resources may be defined and reused as asector dedicated band or a inter-sector shared band in the sectors notadjacent to the inter-sector boundary region. Here, the inter-sectorshared band may be used to cooperatively transmit a signal in twosectors adjacent to the inter-sector boundary region or in a pluralityof sectors including the two sectors. Also, the frequency resourcesdefined as the sector common band are allocated to users located in thecell central regions near the BS, so that they transmit a signal in thesame frequency band by cooperatively using all or some of sectorantennae in a cell. This prevents DCA or inter-sector handover frombeing frequently performed on users moving in the cell central region.

Here, sizes of the sector dedicated band, the inter-sector shared band,and the sector common band may be changed in the total frequencyresources depending on a distribution of users in the cell.

In a second definition scheme according to an exemplary embodiment ofthe present invention, a BS in a multi-sector communication system firstdivides and defines total frequency resources into only a sectordedicated band and a inter-sector shared band.

In this case, frequency resources defined as the sector dedicated bandand the intersector shared band may be used as in the first definitionscheme. Only when a sector common band is required by a user enteringthe cell central region, is inter-sector adjustment performed fordefining the sector common band from among the sector dedicated band orthe inter-sector shared band. Here, the sizes of the sector dedicatedband and the inter-sector shared band in the total frequency resourcesmay be changed depending, for example, on a distribution of users in thecell.

In a third definition scheme according to an exemplary embodiment of thepresent invention, a BS in a multi-sector communication system firstdivides and defines total frequency resources into only a sectordedicated band and a sector common band. In this case, frequencyresources defined as the sector dedicated band and the sector commonband may be used as in the first definition scheme. Only when ainter-sector shared band is required by a user entering the inter-sectorboundary region, is inter-sector adjustment performed for defining theinter-sector shared band from among the sector dedicated band or thesector common band. Here, the inter-sector shared band is not used insectors adjacent to the inter-sector boundary region, but may be definedand reused as a sector dedicated band or a inter-sector shared band inthe sectors not adjacent to the inter-sector boundary region. Also,sizes of the sector dedicated band and the sector common band may bechanged in the total frequency resources depending, for example, on adistribution of users in the cell.

In a fourth definition scheme according to an exemplary embodiment ofthe present invention, a BS in a multi-sector communication system firstdivides and defines total frequency resources into only a inter-sectorshared band and a sector common band. In this case, the frequencyresources defined as the inter-sector shared band and the sector commonband may be used as in the first definition scheme. Only when a sectordedicated band is necessary due to a user entering the sector centralregion, is the sector dedicated band defined and used in theinter-sector shared band or the sector common band through inter-sectoradjustment. Here, the sector dedicated band may be allocated to and usedby users located in other sector central regions in the same cell. Also,sizes of the inter-sector shared band and the sector common band may bechanged in the total frequency resources depending, for example, on adistribution of users in the cell.

In a fifth definition scheme according to an exemplary embodiment of thepresent invention, a BS in a multi-sector communication system firstdefines total frequency resources as only a sector dedicated band. Inthis case, the total frequency resources are defined as the sectordedicated band in all sectors so that each sector frequency reuse factorbecomes 1. Only when a user enters the inter-sector boundary region or acell central region, are a inter-sector shared band and a sector commonband defined and used in the sector dedicated band through inter-sectoradjustment.

In a sixth definition scheme according to an exemplary embodiment of thepresent invention, a BS in a multi-sector communication system firstdefines total frequency resources as only a inter-sector shared band. Inthis case, the total frequency resources are defined as the inter-sectorshared band in all inter-sector boundary regions and used so that afrequency reuse factor is 1 in each inter-sector boundary region. Onlywhen a user enters the sector central region or the cell central region,are a sector dedicated band and a sector common band defined and used inthe inter-sector shared band through inter-sector adjustment.

Also, in a seventh definition scheme according to an exemplaryembodiment of the present invention, a BS in a multi-sectorcommunication system first defines total frequency resources as only asector common band. In this case, the total frequency resources aredefined as the sector common band in common to all sectors and used sothat a frequency reuse factor of the cell becomes 1. Only when a userenters the sector central region or the inter-sector boundary region,are the sector dedicated band and the inter-sector shared band definedfrom among the sector common band through inter-sector adjustment.

Finally, in an eighth definition scheme according to an exemplaryembodiment of the present invention, a BS in a multi-sectorcommunication system does not first define total frequency resources asany band. In this case, only when a user enters the sector centralregion, the inter-sector boundary region, or the cell central region,are the sector dedicated band, the inter-sector shared band, and thesector common band defined and used in the total frequency resourcesthrough inter-sector adjustment. The scheme of transmitting andreceiving a signal through the inter-sector shared band defined bydividing the total available frequency resources in the communicationsystem according to an exemplary embodiment of the present invention asdescribed above, i.e., the scheme of transmitting and receiving a signalthrough the frequency resources of the inter-sector shared band dividedor defined from among the total frequency band to allocate to a userlocated in the inter-sector boundary region may include the followingschemes:

In a first transmission and reception scheme according to an exemplaryembodiment of the present invention, a user located in a inter-sectorboundary region and allocated frequency resources of a inter-sectorshared band in a multi-sector communication system transmits andreceives a signal using only the most neighboring sector antenna. Inthis case, inter-sector shared bands that are not used in twoneighboring inter-sector boundary regions may be defined and reused as asector dedicated band or a inter-sector shared band. Signal quality maybe degraded by antenna gain reduction in a inter-sector boundary regionthat is an edge of a sector antenna beam pattern.

In a second transmission and reception scheme according to an exemplaryembodiment of the present invention, a user located in a inter-sectorboundary region and allocated frequency resources of a inter-sectorshared band in a multi-sector communication system transmits andreceives a signal in the same frequency band by cooperatively using thetwo most neighboring sector antennae. In this case, inter-sector sharedbands that are not used in two neighboring inter-sector boundary regionsmay be defined and reused as the sector dedicated band or theinter-sector shared band. Also, as the user located in the inter-sectorboundary region transmits and receives a signal in the same frequencyband using the two most neighboring sector antennae, the signal qualitydegradation caused by antenna gain reduction in the inter-sectorboundary region can be prevented. Examples of the scheme ofcooperatively transmitting a signal include a scheme by which two sectorantennae adjacent to a inter-sector boundary region transmit the samesignal in the same frequency band to a user located in a inter-sectorboundary region and allocated frequency resources of the inter-sectorshared band; a scheme by which two sector antennae adjacent to ainter-sector boundary region transmit the same information in the samefrequency band; and a scheme by which two sector antennae adjacent to ainter-sector boundary region transmit different information in the samefrequency band.

In a third transmission and reception scheme according to an exemplaryembodiment of the present invention, a user located in a inter-sectorboundary region and allocated frequency resources of a inter-sectorshared band in a multi-sector communication system transmits andreceives a signal in the same frequency band by cooperatively using allor some of sector antennae in a cell. This may consume additional powerand degrade use efficiency of frequency resources of the inter-sectorshared band, but can prevent a ping-pong phenomenon in the inter-sectorboundary region or the cell central region and enable stableinter-sector handover. Examples of the scheme of cooperativelytransmitting a signal include a scheme by which all or some of sectorantennae in a cell transmit the same signal in the same frequency bandto a user located in a inter-sector boundary region and allocatedfrequency resources of the inter-sector shared band; a scheme by whichall or some of sector antennae in a cell transmit the same informationin the same frequency band; and a scheme by which all or some of sectorantennae in a cell transmit different information in the same frequencyband. A scheme of using the inter-sector shared band defined by dividingtotal available frequency resources in a communication system accordingto an exemplary embodiment of the present invention as described abovemay include the following schemes:

First, in a first use scheme according to an exemplary embodiment of thepresent invention, frequency resources of the inter-sector shared bandin a multi-sector communication system are shared among inter-sectorboundary regions. In this case, in order to avoid and minimizeinter-sector interference, the frequency resources of the inter-sectorshared band that are being used in neighboring sectors are not used.Here, sizes of the sector dedicated band and the inter-sector sharedband may be changed, and a part of the inter-sector shared band that isbeing used in a non-adjacent inter-sector boundary region in the cellmay be reused as the sector dedicated band or the inter-sector sharedband.

In a second use scheme according to an exemplary embodiment of thepresent invention, a multi-sector communication system sets ainter-sector boundary region dedicated band for each inter-sectorboundary region. In this case, the multi-sector communication systemdefines inter-sector boundary region dedicated frequency bands definedfrom among the inter-sector shared bands to be orthogonal amonginter-sector boundary regions in the inter-sector boundary regions, andallocates frequency resources only in the orthogonal inter-sectorboundary region dedicated frequency band in the inter-sector boundaryregions. Here, the sizes of the sector dedicated band may be changeddepending on a distribution of users located in each inter-sectorboundary region. A part of the inter-sector shared band that is beingused in a non-adjacent inter-sector boundary region in the cell may bereused as the sector dedicated band or the inter-sector shared band.

The communication system according to an exemplary embodiment of thepresent invention performs DCA to define a total frequency bandaccording to the definition scheme as described above, and flexiblyallocate a sector dedicated band, a inter-sector shared band, and asector common band to the user depending on purposer locations andinterference degree in consideration of users in a sector so that thedefined frequency bands can be used according to the transmission andreception schemes and use schemes. Here, in an embodiment of the presentinvention, when a user moves from a inter-sector boundary region to aneighboring sector central region, from a inter-sector boundary regionto a neighboring cell central region, from cell central region to aneighboring inter-sector boundary region, from a cell central region toa neighboring sector central region, and restrictively, from a sectorcentral region to a neighboring cell central region, current allocatedfrequency resources of the inter-sector shared band or the sector commonband are allowed to continue to be used for a predetermined period oftime and DCA to a frequency band for a region where a user is located isperformed depending on a resource load rate and signal quality whenrequired, thereby simplifying an inter-sector handover procedure andpreventing a ping-pong phenomenon.

A inter-sector boundary region and a sector central region in amulti-sector communication system according to an exemplary embodimentof the present invention will be described in detail with reference toFIG. 1. FIG. 1 illustrates a inter-sector boundary region and a sectorcentral region in a multi-sector communication system according to anexemplary embodiment of the present invention. FIG. 1 illustratesinter-sector boundary regions and sector central regions in 3-sectors ofa clover cell, FIG. 1 b illustrates inter-sector boundary regions andsector central regions in 3-sectors of a hexagonal cell, and FIG. 1 cillustrates inter-sector boundary regions and sector central regions in3-sectors of a hexagonal cell.

Referring to FIG. 1, each of cells 101, 111, and 121 is divided intothree sectors, i.e., a first sector, a second sector, and a thirdsector, each including a inter-sector boundary region and a sectorcentral region. In this case, the inter-sector boundary region andsector central region have a predetermined area ratio (103,113,123). Ineach of the cells 101, 113, and 123, a BS transmits a signal to userslocated in each sector using beam patterns 105, 115, and 125 of sectorantennae. A scheme of dividing, defining and using total frequencyresources as described above in a communication system according to anexemplary embodiment of the present invention will now be described ingreater detail with reference to the accompanying drawings.

FIG. 2 illustrates a scheme of dividing and defining total frequencyresources into a sector dedicated band, a inter-sector shared band and asector common band in a multi-sector communication system according toan exemplary embodiment of the present invention.

Referring to FIG. 2, a BS in the multi-sector communication systemdivides total frequency resources into a sector dedicated band, ainter-sector shared band, and a sector common band according to thefirst definition scheme described above. The BS then allocates frequencyresources defined as the sector dedicated band for each sector to userslocated in the sector central region of the sector, and allocates thefrequency resources defined as the sector dedicated band to userslocated in sector central regions of the other sectors in the same cellfor resource reuse.

The BS also allocates frequency resources defined as the inter-sectorshared band to users located in the inter-sector boundary region in sucha manner that the frequency resources are not used in two sectorsadjacent to the inter-sector boundary region to avoid and minimizeinterference with neighboring sectors in the cell. Here, the BS definesthe frequency resources as the sector dedicated band or the inter-sectorshared band in sectors not adjacent to the inter-sector boundary regionfor resource reuse.

Also, the BS allocates frequency resources defined as the sector commonband to users located in the cell central region near the BS, so thatthey transmit a signal in the same frequency band by cooperatively usingall or some of sector antennae in the cell. This prevents DCA orinter-sector handover from being frequently performed on users moving ina cell central region. The BS changes sizes of the sector dedicatedband, the inter-sector shared band, and the sector common band in thetotal frequency resources depending, for example, on a distribution ofusers in the cell.

FIG. 3 illustrates a scheme of first dividing and defining totalfrequency resources into only a sector dedicated band and a inter-sectorshared band in a multi-sector communication system according to anexemplary embodiment of the present invention.

Referring to FIG. 3, a BS in the multi-sector communication system firstdivides and defines total frequency resources into only a sectordedicated band and a inter-sector shared band according to the seconddefinition scheme described above. The BS then allocates frequencyresources defined as the sector dedicated band for each sector to theusers located in the sector central region of the sector, and alsoallocates frequency resources defined as the sector dedicated band tousers located in sector central regions of other sectors in the samecell for resource reuse.

Also, the BS allocates frequency resources defined as the inter-sectorshared band to users located in the inter-sector boundary region in sucha manner that the frequency resources are not used in two sectorsadjacent to the inter-sector boundary region to avoid and minimizeinterference with the neighboring sectors in the cell. The BS definesthe frequency resources as the sector dedicated band or the inter-sectorshared band in sectors not adjacent to the inter-sector boundary regionfor resource reuse.

The BS changes, for example, sizes of the sector dedicated band and theinter-sector shared band in the total frequency resources depending, forexample, on a distribution of users in the cell. When a user enters thecell central region, the BS performs inter-sector adjustment to definethe sector common band from among the sector dedicated band or theinter-sector shared band according to a predetermined rule, and uses thesector common band.

Also, the BS allocates frequency resources defined as the sector commonband to users located in the cell central region near the BS allocation,so that a user transmits a signal in the same frequency band bycooperatively using all or some sector antennae in a cell, whichprevents DCA or inter-sector handover from being frequently performed onusers moving in the cell central region. Rules by which the BS definesthe sector common band in the sector dedicated band or the inter-sectorshared band will be described with reference to FIGS. 6 to 14.

FIGS. 6 to 8 illustrates an example in which a BS defines the sectorcommon band from among the sector dedicated band or the inter-sectorshared band in a multi-sector communication system according to a firstrule in an exemplary embodiment of the present invention.

Referring to FIGS. 6 to 8, when a user enters the cell central region,the BS sequentially defines the sector common band from among the sectordedicated band or the inter-sector shared band in a predefined order,and allocates the sector common band according to the first rule. If aband to be defined as the sector common band is occupied by a userlocated in the sector central region or the inter-sector boundaryregion, the BS first allocates the band to the user located in the cellcentral region, in which another band is allocated to the user locatedin the sector central region or the inter-sector boundary region. Thatis, according to the first rule, the BS defines the sector common bandfrom among the sector dedicated band as shown in FIG. 6, theinter-sector shared band as shown in FIG. 7, or the sector dedicatedband and the inter-sector shared band as shown in FIG. 8.

FIG. 5 illustrates an example in which a BS defines a sector common bandfrom among a sector dedicated band or a inter-sector shared band in amulti-sector communication system according to a second rule in anexemplary embodiment of the present invention.

FIGS. 9 to 11 illustrates an example in which a BS defines a sectorcommon band from among a sector dedicated band or a inter-sector sharedband in a multi-sector communication system according to a second rulein an exemplary embodiment of the present invention.

Referring to FIGS. 9 to 11, when a user enters the cell central region,the BS defines an empty band in the sector dedicated band or theinter-sector shared band as the sector common band, and allocates thesector common band according to the second rule. If there are no emptyfrequency resources in the sector dedicated bands or the shared band forall inter-sector boundary regions in all sectors, the BS allocatesanother frequency band to users located in the sector central region orthe inter-sector boundary region to prepare an empty band in eachsector, defines the empty band as the sector common band, and allocatesthe same to the users located in the cell central region. That is,according to the second rule, the BS defines the sector common band fromamong the sector dedicated band as shown in FIG. 9, the inter-sectorshared band as shown in FIG. 10, or the sector dedicated band and theinter-sector shared band as shown in FIG. 11.

FIGS. 12 to 14 illustrates an example in which a BS defines a sectorcommon band from among a sector dedicated band or a inter-sector sharedband in a multi-sector communication system according to a third rule inan exemplary embodiment of the present invention.

Referring to FIGS. 12 to 14, in the third rule, a BS sets a reservedcommon band for users located in the cell central region within a sectordedicated band or a inter-sector shared band in advance, and defines andallocates the reserved band as a sector common band when a user entersthe cell central region. If a band to be defined as the sector commonband is occupied by a user located in the sector central region or theinter-sector boundary region, the BS first allocates the band to theuser located in the cell central region, in which another band isallocated to the user located in the sector central region or theinter-sector boundary region. Preferably, a reserved common band is notallocated to users located in the sector central region or theinter-sector boundary region. Here, when the reserved common band isused, the band is used in reverse order of the order in which theresources are allocated to mobile stations located in the cell centralregion. That is, according to the third rule, the BS defines the sectorcommon band from among the sector dedicated band as shown in FIG. 12,the inter-sector shared band as shown in FIG. 13, or the sectordedicated band and the inter-sector shared band as shown in FIG. 14.

FIG. 15 illustrates a scheme of first dividing and defining totalfrequency resources into a sector dedicated band and a sector commonband in a multi-sector communication system according to an exemplaryembodiment of the present invention.

Referring to FIG. 15, a BS in the multi-sector communication systemfirst divides and defines total frequency resources into only a sectordedicated band and a sector common band according to the thirddefinition scheme described above. The BS then allocates frequencyresources defined as the sector dedicated band for each sector to userslocated in the sector central region of the sector, and also allocatesfrequency resources defined as the sector dedicated band to userslocated in sector central regions of other sectors in the same cell forresource reuse.

The BS allocates frequency resources defined as the sector common bandto users located in the cell central region near the BS so that theytransmit a signal in the same frequency band by cooperatively using allor some of sector antennae in a cell. This prevents DCA or inter-sectorhandover from being frequently performed on users moving in the cellcentral region. The BS changes sizes of the sector dedicated band andthe sector common band in the total frequency resources, depending, forexample, on a distribution of users in the cell. When a user enters theinter-sector boundary region, the BS performs inter-sector adjustment todefine the inter-sector shared band in the dedicated band or the sectorcommon band according to a predetermined rule.

Also, the BS allocates frequency resources defined as the inter-sectorshared band to users located in the inter-sector boundary region in sucha manner that the frequency resources are not used in two sectors in thecell adjacent to the inter-sector boundary region in order to avoidinterference with the neighboring sectors. In this case, the frequencyresources may be defined and reused as a sector dedicated band or ainter-sector shared band in sectors not adjacent to the inter-sectorboundary region. Rules by which a BS defines a inter-sector shared bandfrom among a sector dedicated band or a sector common band will bedescribed with reference to FIGS. 8 through 10.

FIGS. 16 to 18 illustrates an example in which a BS defines ainter-sector shared band from among a sector dedicated band or a sectorcommon band according to a first rule in a multi-sector communicationsystem according to an exemplary embodiment of the present invention.

Referring to FIGS. 16 to 18, when a user enters the inter-sectorboundary region, the BS sequentially defines and allocates theinter-sector shared band within the sector dedicated band or the sectorcommon band in a predefined order according to the first rule. If a bandto be defined as the inter-sector shared band is occupied by a userlocated in the sector central region or the cell central region, the BSfirst allocates the band to the user located in the boundary region, inwhich another band is allocated to the user located in the sectorcentral region or the cell central region. That is, according to thefirst rule, the BS defines the inter-sector shared band from among thesector dedicated band as shown in FIG. 16, the sector common band asshown in FIG. 17, or the sector dedicated band and the sector commonband as shown in FIG. 18.

FIGS. 19 to 21 illustrates an example in which a BS defines ainter-sector shared band from among a sector dedicated band or a sectorcommon band according to a second rule in a multi-sector communicationsystem according to an exemplary embodiment of the present invention.

Referring to FIGS. 19 to 21, when a user enters the inter-sectorboundary region, the BS defines and allocates an empty band in thesector dedicated band or the sector common band as the inter-sectorshared band. When there are no empty frequency resources in common tosector dedicated bands for two sectors adjacent to the inter-sectorboundary region or there are no empty frequency resources in the sectorcommon band, the BS selects any one sector, allocates another frequencyband to a user located in a sector central region of the sector toprepare the empty band in common to the two sectors adjacent to theinter-sector boundary region, defines the band as the inter-sectorshared band, and allocates the same to the user located in theinter-sector boundary region. That is, the BS defines the inter-sectorshared band from among the sector dedicated band as shown in FIG. 19,the sector common band as shown in FIG. 20, or the sector dedicated bandand the sector common band as shown in FIG. 21, according to the secondrule.

FIGS. 22 to 24 illustrates an example in which a BS defines ainter-sector shared band from among a sector dedicated band or a sectorcommon band according to a third rule in a multi-sector communicationsystem according to an exemplary embodiment of the present invention.

Referring to FIGS. 22 to 24, in the third rule, a BS sets a reservedshared band for users located in a inter-sector boundary region within asector dedicated band or a sector common band, and defines and allocatesthe reserved shared band as a inter-sector shared band when a userenters the inter-sector boundary region. If a band to be defined as theinter-sector shared band is occupied by a user located in the sectorcentral region or the cell central region, the BS first allocates theband to the user located in the inter-sector boundary region, in whichanother band is allocated to the user located in the sector centralregion or the cell central region. Preferably, the reserved shared bandis not allocated to the user located in the sector central region or thecell central region. Here, when the reserved shared band is used, theband is used in reverse order of the order in which the resources areallocated to mobile stations located in the inter-sector boundaryregion. That is, according to the third rule, the BS defines theinter-sector shared band from among the sector dedicated band as shownin FIG. 22, the sector common band as shown in FIG. 23, or the sectordedicated band and the sector common band as shown in FIG. 24.

FIGS. 25 illustrates a scheme of first dividing and defining totalfrequency resources into and as only a inter-sector shared band and asector common band in a multi-sector communication system according toan exemplary embodiment of the present invention.

Referring to FIG. 25, a BS in the multi-sector communication systemfirst divides and defines total frequency resources into and as only ainter-sector shared band and a sector common band according to thefourth definition scheme described above. The BS then allocatesfrequency resources defined as the inter-sector shared band to userslocated in the inter-sector boundary region in such a manner that thefrequency resources are not used in two sectors in the cell adjacent tothe inter-sector boundary region in order to avoid interference with theneighboring sectors. For resource reuse, the BS defines the frequencyresources as the sector dedicated band or the inter-sector shared bandin sectors not adjacent to the inter-sector boundary region.

The BS allocates frequency resources defined as the sector common bandto users located in the cell central region near the BS so that theytransmit a signal in the same frequency band by cooperatively using allor some sector antennae in a cell. This prevents DCA or inter-sectorhandover from being frequently performed on users moving in the cellcentral region. The BS changes sizes of the inter-sector shared band andthe sector common band within the total frequency resources, depending,for example, on a distribution of users in the cell. When a user entersthe sector central region, the BS performs inter-sector adjustment todefine the sector dedicated band in the inter-sector shared band or thesector common band according to a predetermined rule.

Also, the BS allocates the frequency resources defined as the sectordedicated band for one sector, to the users located in the sectorcentral region of the sector, and, for resource reuse, defines thefrequency resources as the sector dedicated band for other sectors inthe same cell to allocate the same to users located in sector centralregions. In this case, the frequency resources may be defined and reusedas a inter-sector shared band in sectors not adjacent to the sector.Rules by which a BS defines a sector dedicated band from among theinter-sector shared band or the sector common band will be describedwith reference to FIGS. 12 to 14.

FIGS. 26 to 28 illustrates an example in which a BS defines a sectordedicated band from among a inter-sector shared band or a sector commonband according to a first rule in a multi-sector communication systemaccording to an exemplary embodiment of the present invention.

Referring to FIGS. 26 to 28, in the first rule, when a user enters asector central region of one sector, the BS sequentially defines andallocates the sector dedicated band from among the inter-sector sharedband or the sector common band in a predefined order. In this case, whena band to be defined as the sector dedicated band is occupied by a userlocated in the inter-sector boundary region or the cell central region,the BS first allocates the band to the user located in the sectorcentral region, in which another band is allocated to the user locatedin the inter-sector boundary region or the cell central region. That is,the BS defines the sector dedicated band from among the inter-sectorshared band according to the first rule as shown in FIG. 26, the sectorcommon band as shown in FIG. 27, or the inter-sector shared band and thesector common band as shown in FIG. 28.

FIGS. 29 to 31 illustrates an example in which a BS defines a sectordedicated band from among a inter-sector shared band or a sector commonband according to the second rule in a multi-sector communication systemaccording to an exemplary embodiment of the present invention.

Referring to FIGS. 29 to 31, in the second rule, when a user enters asector central region of one sector, a BS defines an empty band in ainter-sector shared band or a sector common band, as the sectordedicated band, and allocates the same. That is, the BS defines thesector dedicated band from among the inter-sector shared band as shownin FIG. 29 according to the second rule, the sector common band as shownFIG. 30, or the inter-sector shared band and the sector common band asshown in FIG. 31.

FIGS. 32 to 34 illustrates an example in which a BS defines a sectordedicated band from among a inter-sector shared band or a sector commonband according to the third rule in a multi-sector communication systemaccording to an exemplary embodiment of the present invention.

Referring to FIGS. 32 to 34, in the third rule, a BS sets a reserveddedicated band for users located in a sector central region within asector boundary band or a sector common band, and defines and allocatesthe reserved dedicated band as a sector dedicated band when a userenters the cell central region. If a band to be defined as the sectordedicated band is occupied by a user located in the inter-sectorboundary region or the cell central region, the BS first allocates theband to the user located in the sector central region, in which anotherband is allocated to the user located in the inter-sector boundaryregion or the cell central region. Preferably, the reserved dedicatedband is not allocated to the user located in the inter-sector boundaryregion or the cell central region. Here, when the reserved dedicatedband is used, the band is used in reverse order of the order in whichthe resources are allocated to users located in the cell central region.That is, according to the third rule, the BS defines the sectordedicated band from among the inter-sector shared band as shown in FIG.32, the sector common band as shown in FIG. 33, or the inter-sectorshared band and the sector common band as shown in FIG. 34.

FIGS. 35 to 38 illustrates a scheme of first defining total frequencyresources as only a sector dedicated band in a multi-sectorcommunication system according to an exemplary embodiment of the presentinvention.

Referring to FIG. 35, a BS in the multi-sector communication systemfirst defines total frequency resources as only a sector dedicated bandaccording to the fifth definition scheme described above. The BS thenallocates frequency resources defined as the sector dedicated band foreach sector to users located in the sector central region of the sector,and also allocates the frequency resources defined as the sectordedicated band to users located in sector central regions of the othersectors in the same cell for resource reuse. When a user enters theinter-sector boundary region, the BS performs inter-sector adjustment todefine the inter-sector shared band in the sector dedicated bandaccording to a predetermined rule.

Also, the BS allocates frequency resources defined as the inter-sectorshared band to users located in the inter-sector boundary region in sucha manner that the frequency resources are not used in sectors adjacentthe inter-sector boundary region to avoid interference with neighboringsectors in the cell. For resource reuse, the BS defines the frequencyresources as the sector dedicated band or the inter-sector shared bandin sectors not adjacent to the inter-sector boundary region. When a userenters the cell central region, the BS performs inter-sector adjustmentto define the sector common band in the sector dedicated band accordingto a predetermined rule.

Also, the BS allocates frequency resources defined as the sector commonband to users located in the cell central region near the BS so thatthey transmit a signal in the same frequency band by cooperatively usingall or some sector antennae in a cell. This prevents DCA or inter-sectorhandover from being frequently performed on users moving in the cellcentral region. Rules by which the BS defines the sector common bandfrom among the sector dedicated band sector or the boundary regionshared band will be described with reference to FIGS. 15 b to 15 d.

Referring to FIG. 36, when a user enters the inter-sector boundaryregion or the cell central region, the BS sequentially defines theinter-sector shared band or the sector common band from among the sectordedicated band in a predefined order according to a first rule throughinter-sector adjustment, and allocates the same. If a band to be definedas the inter-sector shared band or the sector common band is occupied byusers located in sector central regions of sectors in the cell, the BSfirst allocates the band to the user located in the inter-sectorboundary region or the cell central region, in which another band isallocated to the other users located in the sector central regions ofsectors.

Referring to FIG. 37, when a user enters the inter-sector boundaryregion or the cell central region, the BS defines an empty band in thesector dedicated band as the inter-sector shared band or the sectorcommon band according to the second rule, and allocates the same. When auser enters the inter-sector boundary region and there is no empty bandin common to the sector dedicated bands for two sectors adjacent to theinter-sector boundary region frequency resources or when a users entersthe cell central region and there are no empty frequency resources incommon to all sector dedicated bands, the BS allocates another frequencyband to a user located in the sector central region to prepare the emptyband in common to the sector dedicated bands for the two sectorsadjacent to the inter-sector boundary region, defines the band as theinter-sector shared band, and allocates the same to the user located inthe inter-sector boundary region, or prepares the empty band in commonto all the sectors, defines the band as the sector common band, andallocates the same to the user located in the cell central region.

Referring to FIG. 38, in the third rule, a BS sets a reserved sharedband or a reserved common band for users located in a inter-sectorboundary region or a cell central region within a sector dedicated band,and defines and allocates the reserved shared band as a inter-sectorshared band or a sector common band when a user enters the inter-sectorboundary region or the cell central region. If a band to be defined asthe inter-sector shared band or the sector common band is occupied by auser located in the sector central region, the BS first allocates theband to the user located in the inter-sector boundary region or the cellcentral region, in which another band is allocated to the user locatedin the sector central region. Here, the BS changes sizes of the reservedshared band and the reserved common band depending, for example, on adistribution of users in the cell. Preferably, the reserved shared bandor the reserved common band is not allocated to the user located in thesector central region. Here, when the reserved shared band or thereserved common band is used, the band is used in reverse order of theorder in which the resources are allocated to mobile stations located inthe inter-sector boundary region or the cell central region.

FIGS. 39 to 42 illustrates a scheme of first defining total frequencyresources as only a inter-sector shared band in a multi-sectorcommunication system according to an exemplary embodiment of the presentinvention.

Referring to FIG. 39, a BS in the multi-sector communication systemfirst defines the total frequency resources as only a inter-sectorshared band according to the sixth definition scheme described above.The BS then allocates frequency resources defined as the inter-sectorshared band to users located in the inter-sector boundary region in sucha manner that the frequency resources are not used in two sectors in thecell adjacent to the inter-sector boundary region in order to avoidinterference with the neighboring sectors. For resource reuse, the BSdefines the frequency resources as sector dedicated bands orinter-sector shared bands in sectors not adjacent to the inter-sectorboundary region. When a user enters the sector central region, the BSperforms inter-sector adjustment to define frequency resources in theinter-sector shared band as the sector dedicated band according to apredetermined rule.

The BS also allocates frequency resources defined as a sector dedicatedband for one sector to users located in the sector central region of thesector, and, for resource reuse, defines the frequency resources as thesector dedicated band for other sectors in the same cell to allocate thesame to users located in sector central regions. For additional resourcereuse, the BS defines the frequency resources as the inter-sector sharedband in non-neighboring sectors. When a user enters the cell centralregion, the BS performs inter-sector adjustment to define the sectorcommon band in the sector dedicated band according to a predeterminedrule.

Also, the BS allocates the frequency resources defined as the sectorcommon band to users located in cell central regions near the BS so thatthey transmit a signal in the same frequency band by cooperatively usingall or some of sector antennae in a cell. This prevents DCA orinter-sector handover from being frequently performed on users moving inthe cell central region. Rules by which the BS defines the sectordedicated band and the sector common band from among the inter-sectorshared band will be described with reference to FIGS. 16 b to 16 d.

Referring to FIG. 40, when a user enters the sector central region orthe cell central region, the BS performs inter-sector adjustment tosequentially define the sector dedicated band or the sector common bandin the inter-sector shared band in a predefined order according to afirst rule, and allocate the same. If a band to be defined as the sectordedicated band or the sector common band is occupied by a user locatedin the inter-sector boundary region, the BS first allocates the band tothe user located in the sector central region or the cell central regionafter allocating another band to the other users.

Referring to FIG. 41, when a user enters the sector central region orthe cell central region, the BS defines an empty band in theinter-sector shared band as the sector dedicated band or the sectorcommon band according to the second rule and allocates the same to theuser. When a user enters the cell central region and there is no emptyband in common to all inter-sector shared bands, the BS performsinter-sector adjustment to allocate another frequency band to a userlocated in the inter-sector boundary region to prepare the empty band incommon to all the inter-sector shared bands, define the empty band asthe sector common band, allocate the same to the users located in thecell central region.

Referring to FIG. 42, in the third rule, a BS sets a reserved dedicatedband or a reserved common band for users located in a sector centralregion or a cell central region within a sector boundary band, anddefines and allocates the reserved band as a sector dedicated band or asector common band when a user enters the sector central region or thecell central region. If a band to be defined as the sector dedicatedband or the sector common band is occupied by a user located in theinter-sector boundary region, the BS first allocates the band to theuser located in the sector central region or the cell central region, inwhich another band is allocated to the user located in the inter-sectorboundary region. Here, the BS changes sizes of the reserved dedicatedband and the reserved common band depending, for example, on adistribution of users in the cell. Preferably, the reserved dedicatedband or the reserved common band is not allocated to the user located inthe inter-sector boundary region. Here, the reserved dedicated band orthe reserved common band is used in reverse order of the order in whichthe resources are allocated to mobile stations located in the cellcentral region.

FIGS. 43 to 46 illustrates a scheme of first defining total frequencyresources as only a sector common band in a multi-sector communicationsystem according to an exemplary embodiment of the present invention.

Referring to FIG. 43, a BS in the multi-sector communication systemfirst defines total frequency resources as only the resource sectorcommon band according to the seventh definition scheme described above.The BS then allocates frequency resources defined as the sector commonband to users located in cell central regions near the BS so theytransmit a signal in the same frequency band by cooperatively using allor some sector antennae in a cell. This prevents DCA or handover frombeing frequently performed on users moving in the cell central regionnear the BS. When a user enters the sector central region, the BSperforms inter-sector adjustment to define the sector dedicated band inthe common band according to a predetermined rule.

The BS also allocates frequency resources defined as the sectordedicated band for one sector to users located in the sector centralregion of the sector, and, for resource reuse, defines the frequencyresources as a sector dedicated band for the other sectors in the samecell to allocate the same to users located in a sector central region ofthe sector. For additional resource reuse, the BS defines the frequencyresources as the inter-sector shared band in non-neighboring sectors.When a user enters the inter-sector boundary region, the BS performsinter-sector adjustment to define the inter-sector shared band in thecommon band according to a predetermined rule.

Also, the BS allocates frequency resources defined as the inter-sectorshared band, to users located in the inter-sector boundary region insuch a manner that the frequency resources are not used in two sectorsin the cell adjacent to the inter-sector boundary region in order toavoid interference with the neighboring sectors. For resource reuse, theBS defines the frequency resources as the sector dedicated band or theinter-sector shared band in sectors not adjacent to the inter-sectorboundary region. Here, the BS defines the frequency resources as theinter-sector shared band in non-neighboring sectors for resource reuse.Rules by which a BS in a multi-sector communication system defines asector dedicated band and a inter-sector shared band from among a sectorcommon band will be described with reference to FIGS. 17 b to 17 d.

Referring to FIG. 44, when a user enters the sector central region orthe inter-sector boundary region, the BS sequentially defines andallocates a sector dedicated band or a inter-sector shared band fromamong a sector common band in a predefined order through inter-sectoradjustment, according to a first rule. If a band to be defined as thesector dedicated band or the inter-sector shared band is occupied byusers located in a cell central region near the BS, the BS firstallocates the band to the user located in the sector central region orthe inter-sector boundary region after allocating another band to theusers located in the cell central region.

Referring to FIG. 45, when a user enters the sector central region orthe inter-sector boundary region, the BS defines an empty band in thesector common band as the sector dedicated band or the inter-sectorshared band according to the second rule, and allocates the same. When auser enters the inter-sector boundary region and there are no emptyfrequency resources in common to the sector common bands for two sectorsadjacent to the inter-sector boundary region, the BS allocates anotherband to a user who is using the sector dedicated band defined from amongthe sector common band in the neighboring two sectors, prepares theempty band in common to the sector common bands for the two sectorsadjacent to the inter-sector boundary region, defines the band as theinter-sector shared band for the inter-sector boundary region, andallocates the same to the user located in the inter-sector boundaryregion.

Referring to FIG. 46, in the third rule, a BS sets a reserved dedicatedband or a reserved shared band for users located in a sector centralregion or a inter-sector boundary region within a sector common band,and defines and allocates the reserved band as a sector dedicated bandor a inter-sector shared band when a user enters the sector centralregion or the inter-sector boundary region. If a band to be defined asthe sector dedicated band or the inter-sector shared band is occupied bya user located in the cell central region, the BS first allocates theband to the user located in the sector central region or theinter-sector boundary region, in which another band is allocated to theuser located in the cell central region. Here, the BS changes sizes ofthe reserved dedicated band and the reserved shared band depending, forexample, on a distribution of users in the cell. Preferably, thereserved dedicated band or the reserved shared band is not allocated tousers located in the cell central region or the cell central region.Here, when the reserved dedicated band or the reserved shared band isused, it is used in reverse order of the order in which the resourcesare allocated to mobile stations located in the sector central region orthe inter-sector boundary region.

FIGS. 47 to 50 illustrates a scheme in which total frequency resourcesare first not defined as any band in a multi-sector communication systemaccording to an exemplary embodiment of the present invention.

Referring to FIG. 47, a BS in the multi-sector communication systemfirst does not define the total frequency resources as any bandaccording to the eighth definition scheme described above. When a userenters the sector central region, the BS then performs inter-sectoradjustment to define the sector dedicated band in the total frequencyresources according to a predetermined rule.

The BS allocates frequency resources defined as a sector dedicated bandfor one sector to users located in the sector central region of thesector, and, for resource reuse, defines the frequency resources as thesector dedicated band for other sectors in the same cell to allocate thesame to users located in a sector central region of the sector. Foradditional resource reuse, the BS defines the frequency resources as theinter-sector shared band in non-neighboring sectors. When a user entersthe inter-sector boundary region, the BS performs inter-sectoradjustment to define the inter-sector shared band in the total frequencyresources according to a predetermined rule.

Also, the BS allocates frequency resources defined as the inter-sectorshared band to users located in the inter-sector boundary region in sucha manner that the frequency resources are not used in two sectors in thecell adjacent to the inter-sector boundary region in order to avoidinterference with the neighboring sectors. For resource reuse, the BSdefines the frequency resources as the sector dedicated band or theinter-sector shared band in sectors not adjacent to the inter-sectorboundary region. When a user enters the cell central region, the BSperforms inter-sector adjustment to define the sector common band in thetotal frequency resources according to a predetermined rule.

The BS also allocates frequency resources defined as the sector commonband to users located in cell central regions near the BS so that theytransmit a signal in the same frequency band by cooperatively using allor some sector antennae in a cell. This prevents DCA or handover frombeing frequently performed on users moving in the cell central region.Rules by which a BS defines a sector dedicated band, a inter-sectorshared band, and a sector common band in total frequency resources willbe described with reference to FIGS. 18 b to 18 d.

Referring to FIG. 48, when a user enters the sector central region, theinter-sector boundary region, or the cell central region, the BSperforms inter-sector adjustment to sequentially define the sectordedicated band, the inter-sector shared band, and the sector common bandin the total frequency resources in a predefined order and allocate thesame.

Referring to FIG. 50, when a user enters the sector central region, theinter-sector boundary region, and the cell central region, the BSdefines an empty band in the total frequency resources as the sectordedicated band, the inter-sector shared band, and the sector common bandaccording to the second rule, and allocates the same to the user. When auser enters the inter-sector boundary region and there are no emptyfrequency resources in common to two sectors adjacent to theinter-sector boundary region, or when a users enters the cell centralregion and there are no empty frequency resources in common to all thesectors, the BS allocates another frequency band to a user located inthe sector central region, prepares the empty band in common to the twosectors adjacent to the inter-sector boundary region, defines the bandas the inter-sector shared band, and allocates the same to the userlocated in the inter-sector boundary region, or prepares the empty bandin common to all the sectors, defines the band as the sector commonband, and allocates the same to users located in the cell centralregion.

Referring to FIG. 51, a BS sets a reserved dedicated band, a reservedshared band, or a reserved common band for users located in a sectorcentral region, a inter-sector boundary region, or a cell central regionwithin total frequency resources, and defines and allocates the reservedband as a sector dedicated band, a inter-sector shared band, or a sectorcommon band when a user enters the sector central region, theinter-sector boundary region, or the cell central region. If a band tobe defined as the band for one region is occupied by a user located inthe other region, the BS first allocates the band to the user located inthe region, in which another band is allocated to the user located inthe other region. In this case, the BS may change sizes of the reserveddedicated band, the reserved shared band, and the reserved common banddepending, for example, on a distribution of users in the cell.Preferably, the reserved band for one region is not allocated to userslocated in the other regions. Here, when the reserved band for the otherregion is used, it is used in reverse order of the order in which theresources are allocated to users located in relevant region. A scheme ofusing a inter-sector shared band defined by dividing total availablefrequency resources, i.e., a scheme of transmitting and receiving asignal through the frequency resources of the inter-sector shared banddivided or defined from among the total frequency band to allocate to auser located in the inter-sector boundary region, as described above, ina communication system according to an exemplary embodiment of thepresent invention will be described with reference to FIGS. 51 to 53.

FIGS. 51 to 53 illustrates a scheme of using a inter-sector shared bandin a multi-sector communication system according to an exemplaryembodiment of the present invention. FIGS. 19 a to 19 c illustratesignal transmission and reception schemes using the frequency resourcesof the inter-sector shared band defined from among a total frequencyband to be allocated to users located in the inter-sector boundaryregion according to the three transmission and reception schemes, asdescribed above, in a multi-sector communication system.

Referring to FIG. 51, the multi-sector communication system transmitsand receives a signal using only the most neighboring sector antennaaccording to the first transmission and reception scheme describedabove. That is, a user located in the inter-sector boundary region andallocated the frequency resources of the inter-sector shared band isconnected only to the most neighboring sector antenna to transmit andreceive a signal. For reuse, the multi-sector communication systemdefines inter-sector shared bands for the respective sectors that arenot used in two neighboring inter-sector boundary regions, as the sectordedicated band or as the inter-sector shared band. Here, in theinter-sector boundary region that is an edge of a sector antenna beampattern, antenna gain reduction may result in signal qualitydegradation.

More specifically, although a first user and a second user are bothlocated in the first inter-sector boundary region, the most neighboringsector antennae differ, and the first user is connected to the firstsector antenna and the second user is connected to the second sectorantenna. A third user is located in the second inter-sector boundaryregion and is most adjacent to a second sector antenna. Accordingly, thethird user is connected to the second sector antenna. In this case, thethird sector antenna allocates a frequency band used for the firstsector antenna to transmit and receive a signal to and from the firstuser and a frequency band used for the second sector antenna to transmitand receive a signal to and from the second user, as the sectordedicated band, to users located in a third sector central region. Also,the first sector antenna allocates a frequency band used for the thirdsector antenna to transmit and receive a signal to and from the thirduser, as the sector dedicated band, to a user located in the firstsector central region.

Referring to FIG. 52, the multi-sector communication system transmitsand receives a signal in the same frequency band by cooperatively usingthe two most neighboring sector antennae according to the secondtransmission and reception scheme described above. That is, a userlocated in the inter-sector boundary region and allocated the frequencyresources of the inter-sector shared band transmits and receives asignal by cooperatively using the two most neighboring sector antennae.For reuse, the multi-sector communication system defines inter-sectorshared bands for respective sectors that are not used in two neighboringinter-sector boundary regions, as the sector dedicated band or theinter-sector shared band. Also, since a user located in the inter-sectorboundary region that is an edge of the sector antenna beam patterntransmits and receives a signal in the same frequency band bycooperatively using the two most neighboring sector antennae, signalquality degradation caused by antenna gain reduction in the inter-sectorboundary region can be prevented.

Here, a scheme by which the two sector antennae transmit and receive asignal to and from the user includes a 2-1 transmission and receptionscheme in which the two most neighboring sector antennae transmit thesame signal in the same frequency band to a user located in theinter-sector boundary region and allocated the frequency resource of theinter-sector shared band, a 2-2 transmission and reception scheme inwhich the two most neighboring sector antennae transmit the sameinformation in the same frequency band to a user located in theinter-sector boundary region and allocated the frequency resources ofthe inter-sector shared band, and a 2-3 transmission and receptionscheme in which the two most neighboring sector antennae transmitdifferent information in the same frequency band to a user located inthe inter-sector boundary region and allocated the frequency resourcesof the inter-sector shared band. In this case, the scheme by which thetwo sector antennae transmit a signal may be applied, for example, tospatial division multiple access (“SDMA”) and space time code (“STC”).

More specifically, since both the first user and the second user arelocated in the first inter-sector boundary region, they are connected tothe two most neighboring sector antennae, i.e., the first sector antennaand the second sector antenna to cooperatively transmit and receive asignal in the same frequency band. Since the third user is located in asecond inter-sector boundary region, it is connected to the second andthird most neighboring sector antennae to cooperatively transmit andreceive a signal in the same frequency band. In this case, the thirdsector antenna allows the frequency band used for the first sector andthe second sector antenna transmit and receive a signal to and from thefirst user and the second user, to be allocated, as a sector dedicatedband, to a user located in the third sector central region. Also, thefirst sector antenna allows the frequency band used for the secondsector and the third sector antenna to transmit and receive a signal toand from the third user to be allocated, as the sector dedicated band,to the user located in the first sector central region.

Referring to FIG. 53, the multi-sector communication system transmitsand receives a signal in the same frequency band by cooperatively usingall or some sector antennae in one cell according to the thirdtransmission and reception scheme described above. In this case, a userlocated in the inter-sector boundary region and allocated the frequencyresources of the inter-sector shared band transmits and receives asignal in the same frequency band by cooperatively using all or somesector antennae in one cell. As all or some of the sector antennae inone cell cooperatively transmit and receive a signal in the samefrequency band to and from the user located in the inter-sector boundaryregion, it may lead to additional power consumption and degraded useefficiency of the frequency resources of the inter-sector shared band.However, when the user moves from the inter-sector boundary region orthe cell central region to a neighboring sector, stable inter-sectorhandover is possible.

Examples of the scheme by which all or some sector antennae transmit andreceive a signal to and from a user include a 3-1 transmission andreception scheme by which all or some sector antennae transmit andreceive the same signal in the same frequency band to the user locatedin the inter-sector boundary region and allocated the frequencyresources of the inter-sector shared band; a 3-2 transmission andreception scheme by which all or some sector antennae transmit the sameinformation in the same frequency band to the user located in theinter-sector boundary region and allocated the frequency resources ofthe inter-sector shared band; and a 3-3 transmission and receptionscheme by which all or some sector antennae transmit differentinformation in the same frequency band to the user located in theinter-sector boundary region and allocated the frequency resources ofthe inter-sector shared band. This may apply to SDMA and STC.

That is, since all of the first, second and third users are located inthe inter-sector boundary region, they are simultaneously connected toall sector antennae and transmit and receive a signal in the samefrequency band cooperatively. The scheme of using the inter-sectorshared band defined by dividing total available frequency resources asdescribed above in the multi-sector communication system according to anexemplary embodiment of the present invention, i.e., the scheme of usingthe frequency resources of the inter-sector shared band defined fromamong a total frequency band to be allocated to users located in theinter-sector boundary region will now be described with reference to theaccompanying drawings.

FIGS. 54 to 56 illustrates a scheme of using a inter-sector shared bandin a 3-sector cell of a multi-sector communication system according toan exemplary embodiment of the present invention.

Referring to FIG. 54, in the multi-sector communication system, thefrequency resources of the inter-sector shared band are shared amonginter-sector boundary regions according to the first use schemedescribed above. Also, in order to avoid inter-sector interference, thefrequency resources of the inter-sector shared band that are being usedin neighboring sectors are not used. In this case, the frequencyresources may be reused as the sector dedicated band or the inter-sectorshared band for non-adjacent sectors. Here, the multi-sectorcommunication system changes a size of the inter-sector shared band inthe total frequency resources depending, for example, on a distributionof users in a cell.

More specifically, the frequency resources of the inter-sector sharedband are shared among inter-sector boundary regions in such a mannerthat a user located in the inter-sector boundary region and allocatedthe frequency resources of the inter-sector shared band transmits andreceives a signal in the same frequency band by cooperatively using thetwo most neighboring sector antennae.

Referring to FIG. 55, the multi-sector communication system divides ainter-sector shared band into inter-sector boundary regions according tothe second use scheme described above. In this case, the multi-sectorcommunication system defines the boundary region dedicated frequencybands from among the inter-sector shared band to be orthogonal amonginter-sector boundary regions and allocates the frequency resources tobe orthogonal among the inter-sector boundary regions. Here, themulti-sector communication system changes sizes of the sector dedicatedband and the inter-sector shared band in the total frequency resourcesdepending, for example, on a distribution of users in the cell.

Referring to FIG. 56, the multi-sector communication system divides theinter-sector shared band by the number of sectors to be orthogonal toone another in a 3-sector cell according to the second use schemedescribed above, and allocates a dedicated shared band to eachinter-sector boundary region. Here, the multi-sector communicationsystem changes sizes of the dedicated shared bands for the inter-sectorboundary region depending, for example, on a distribution of users inthe inter-sector boundary region. Also, in the 3-sector cell, theinter-sector shared bands are divided and used in the inter-sectorboundary regions, and a user located in the inter-sector boundary regiontransmits and receives a signal in the same frequency band bycooperatively using the two most neighboring sector antennae. In thiscase, in order to avoid inter-sector interference in each sector, unusedfrequency resources of the inter-sector shared band may be reused as thesector dedicated band.

FIG. 57 and 58 illustrates a scheme of using a inter-sector shared bandin a 4-sector cell of a multi-sector communication system according toan exemplary embodiment of the present invention.

Referring to FIG. 57, the multi-sector communication system divides ainter-sector shared band by the number of sectors to be orthogonal toone another in the 4-sector cell according to the second use schemedescribed above and allocates a dedicated shared band to eachinter-sector boundary region. Here, the multi-sector communicationsystem changes sizes of the dedicated shared bands for the inter-sectorboundary region depending, for example, on a distribution of users inthe inter-sector boundary region. In this case, the multi-sectorcommunication system allows the frequency resources of the inter-sectorshared band to be reused in non-neighboring inter-sector boundaryregions. Also, the multi-sector communication system definesinter-sector shared bands that are not used in two neighboringinter-sector boundary regions, as the sector dedicated band, for reuse.

Referring to FIG. 58, the multi-sector communication system divides ainter-sector shared band into two bands to be orthogonal to each otherin a 4-sector cell according to the second use scheme described aboveand allocates the same as a dedicated shared band for each inter-sectorboundary region. In this case, the frequency resources of theinter-sector shared band allocated to the inter-sector boundary regionare not used by sectors adjacent to the inter-sector boundary region inorder to avoid interference with neighboring sectors in the cell. Inthis case, the multi-sector communication system allows the frequencyresources of the inter-sector shared band to be reused innon-neighboring inter-sector boundary regions.

FIGS. 59 to 61 illustrates a scheme of using a inter-sector shared bandin a 6-sector cell of a multi-sector communication system according toan exemplary embodiment of the present invention.

Referring to FIG. 59, the multi-sector communication system divides ainter-sector shared band by the number of sectors to be orthogonal toone another in a 6-sector cell according to the second use schemedescribed above, and allocates a dedicated shared band to eachinter-sector boundary region. Here, the multi-sector communicationsystem changes sizes of the dedicated shared bands for the inter-sectorboundary region depending, for example, on a distribution of users inthe inter-sector boundary region. In this case, the multi-sectorcommunication system allows the frequency resources of the inter-sectorshared band to be reused in non-neighboring inter-sector boundaryregions. Also, the multi-sector communication system definesinter-sector shared bands that are not used in two neighboringinter-sector boundary regions, as the sector dedicated band, for reuse.

Referring to FIG. 60, the multi-sector communication system divides ainter-sector shared band into three bands to be orthogonal to oneanother in a 6-sector cell according to the second use scheme describedabove, and allocates the same as a dedicated shared band for eachinter-sector boundary region. In this case, the frequency resources ofthe inter-sector shared band allocated to the inter-sector boundaryregion are not used by sectors adjacent to the inter-sector boundaryregion in order to avoid interference with neighboring sectors in thecell. In this case, the multi-sector communication system allows thefrequency resources of the inter-sector shared band to be reused innon-neighboring inter-sector boundary regions. Also, the multi-sectorcommunication system defines the inter-sector shared band that is notused in two neighboring inter-sector boundary regions, as the sectordedicated band, for reuse.

Referring to FIG. 61, the multi-sector communication system divides ainter-sector shared band into two bands to be orthogonal to each otherin a 6-sector cell according to the second using scheme described above,and allocates the same as a dedicated shared band for each inter-sectorboundary region. In this case, the frequency resources of theinter-sector shared band allocated to the inter-sector boundary regionare not used by sectors adjacent to the inter-sector boundary region inorder to avoid interference with neighboring sectors in the cell. Inthis case, the multi-sector communication system allows the frequencyresources of the inter-sector shared band to be reused innon-neighboring inter-sector boundary regions.

FIG. 62 and 63 illustrates a scheme of using a inter-sector shared bandin a 3-sector cell of a multi-sector communication system according toan exemplary embodiment of the present invention.

Referring to FIG. 62, the multi-sector communication system usesfrequency resources through the scheme of using the frequency resourcesof the inter-sector shared band into dedicated bands to be orthogonal toeach other in each inter-sector boundary region in a 3-sector cellaccording to the second use scheme described above. In this case, theinter-sector shared band is shared by a user located in the inter-sectorboundary region and allocated the frequency resources of theinter-sector shared band by transmitting and receiving a signal in thesame frequency band by cooperatively using the two sector antennae mostadjacent to the user.

Referring to FIG. 63, the multi-sector communication system divides thefrequency resources of the inter-sector shared band in a 3-sector cellaccording to the second use scheme described above and uses the samevariably. That is, the multi-sector communication system changes a sizeof the dedicated band defined from among each inter-sector boundaryregion depending, for example, on a distribution of users located ineach inter-sector boundary region. An example in which DCA is performedin a multi-sector communication system according to an exemplaryembodiment of the present invention will now be described in detail withreference to the accompanying drawings.

First, the multi-sector communication system according to an exemplaryembodiment of the present invention uses the following information,i.e., parameters for DCA:

A parameter used for identifying the inter-sector boundary region andthe sector central region.

A parameter used for identifying locations of the cell central regionand a cell non-center region.

After obtaining the information for the DCA, a multi-sectorcommunication system performs the DCA. More specifically, when themulti-sector communication system obtains the information for the DCAbetween the inter-sector shared band and the sector dedicated band, itperforms the DCA based on the obtained information.

For example, in a downlink (“DL”), the MS of the user simultaneouslyreceives signals from BSs for the sectors located in a cell centralregion. In this case, the signals differ in intensity among userlocations according to a designed antenna beam pattern. First, the BSmeasures a power ratio between two signals having the largest intensityupon initialization, and compares it with a boundary value. When themeasured value is smaller than the boundary value, the user isdetermined not to be located in the inter-sector boundary region. Whenthe measured value is greater than the boundary value, the user isdetermined to be located in the sector central region. The MSperiodically measures and compares the intensities of the largestsignals from two sector antennae to determine a sector central region ora inter-sector boundary region in which the user is located. Here, forexample, a pilot signal is used to measure the intensity of the signaltransmitted from each sector antenna.

The MS then transmits the power ratio between the two largest signals tothe BS. Based on the power ratio, the BS determines a sector centralregion or inter-sector boundary region in which the user is located,whether DCA is needed, and which of the antennae is used to transmit andreceive a signal for resource allocation and system operation.

In an uplink (“UL”), a signal from the MS of the user is simultaneouslyreceived by all sector antennae for BSs located in the cell centralregion. In this case, the BS measures signals from the two sectorantennae that receive the largest signals from the MS, compares thesignal with a boundary value to determine a central region or ainter-sector boundary region in which the user is located. The BS thenmeasures a signal of the two sector antennae that receive the largestsignal from the MS, and compares the signal with the boundary value todetermine a sector central region or inter-sector boundary region inwhich the user is located, whether DCA is needed, and which of theantennae is used to transmit and receive a signal for resourceallocation and system operation.

When information for DCA between the sector common band and another bandis obtained, the multi-sector communication system performs DCA based onthe obtained information. That is, in a communication system in which asector common band is set in total frequency resources, information forDCA between the sector common band and the inter-sector shared band orthe sector dedicated band is necessary. The information for DCA betweenthe inter-sector shared band and the sector dedicated band as describedabove is used to determine the location of the user. When DCA isperformed, the MS measures SINR of its signal excluding an interferencesignal and compares the measured SINR with a center reference value.When the measured value is smaller than the center reference value, theuser is determined not to be located in the cell central region. Whenthe measured value is greater than the center reference value, the useris determined to be located in the cell central region. The MSperiodically measures and compares the SINR to determine whether theuser is located in the cell central region or not.

The MS transmits the SINR to the BS. Upon receipt of the SINR, the BSdetermines whether the user is located in the cell central region ornot, whether DCA is needed, and which of the antennae is used totransmit and receive data for resource allocation and system operation.

Also, the multi-sector communication system according to an exemplaryembodiment of the present invention performs DCA to dynamically allocatethe sector dedicated band, the inter-sector shared band, and the sectorcommon band to users in a sector according to user locations and aninterference degree that depend on mobility of the users, in order toefficiently use the total frequency resources including the frequencybands defined as described above. For convenience of description, it isassumed that a multi-sector communication system according to anexemplary embodiment of the present invention performs DCA depending onthe mobility of the user in a 3-sector cell. Although the embodiment ofthe present invention will describe DCA in a 3-sector cell, the presentinvention may apply to DCA in a multi-sector cell including a 4-sectorcell and a 6-sector cell.

Also, in the embodiment of the present invention, the scheme of sharingthe inter-sector shared band, for example, a scheme by which a userlocated in the inter-sector boundary region and allocated the frequencyresources of the inter-sector shared band transmits and receives asignal in the same frequency band by cooperatively using the two mostneighboring sector antennae, will be described. Here, the multi-sectorcommunication system according to an exemplary embodiment of the presentinvention performs DCA by using a first DCA scheme of having thefrequency resources, which are allocated to and used by a user uponperforming DCA to a different frequency band from an existing frequencyband, returned fully as an initially set band in all sectors, and asecond DCA scheme of having the frequency resources returned partiallyas an initially set band only in some of the sectors. An example inwhich DCA is performed when a user moves from a inter-sector boundaryregion to a sector central region will now be described.

FIG. 61 and 65 illustrates an example in which DCA is performed when auser moves from a inter-sector boundary region to a sector centralregion in a multi-sector communication system according to an exemplaryembodiment of the present invention. In FIG. 64 and 65, the multi-sectorcommunication system allocates a sector dedicated band to a user who iscurrently using a inter-sector shared band and has the inter-sectorshared band returned from the user.

Referring to FIG. 64, the multi-sector communication system fullyreturns the frequency resources of the inter-sector shared band used bythe user, as the inter-sector shared band in all the sectors accordingto a first DCA scheme. That is, since the user moves from a firstinter-sector boundary region to a first sector central region, the userreturns the previous inter-sector shared band and is allocated thesector dedicated band for the first sector. In this case, a userallocated the same frequency band as the inter-sector shared band and asthe sector dedicated band for the third sector, returns the band and isallocated the sector dedicated band for the third sector.

Referring to FIG. 65, the multi-sector communication system partiallyreturns, as the inter-sector shared band, the frequency resources of theinter-sector shared band used by the user in only two neighboringsectors to which the user is connected according to the second DCAscheme. That is, since the user moves from the first inter-sectorboundary region to the first sector central region, the user returns theprevious inter-sector shared band and is allocated the sector dedicatedband for the first sector. In this case, the user allocated the samefrequency band as the inter-sector shared band and the sector dedicatedband for the third sector allocation, continues to use the band withoutreturning the same.

Accordingly, when the user moves from the inter-sector boundary regionto the sector central region, the multi-sector communication systemimmediately performs a DCA procedure to allocate the sector dedicatedband to the user and have the inter-sector shared band in use returnedfrom the user. Or, when the user stays in the sector central region fora predetermined period of time or lacks the frequency resources of theinter-sector shared band while using the current frequency resources ofthe inter-sector shared band, the multi-sector communication systemperforms a DCA procedure to allocate the sector dedicated band to theuser and have the inter-sector shared band in use returned from theuser.

FIGS. 66 to 69 illustrates an example in which DCA is performed when auser moves from a inter-sector boundary region to a sector centralregion in a multi-sector communication system according to an exemplaryembodiment of the present invention. In FIGS. 66 to 69, the multi-sectorcommunication system defines the sector dedicated band from among thesector common band, allocates the same to a user who is currently usingthe inter-sector shared band, and has the inter-sector shared bandreturned from the user.

Referring to FIG. 66, the multi-sector communication system allows thefrequency resources of the sector dedicated band defined from among thesector common band allocated to the user, to be reused as the sectordedicated band in other sectors according to the first DCA scheme. Thatis, the frequency resources of the inter-sector shared band used by theuser are fully returned as the inter-sector shared band in all thesectors.

Referring to FIG. 67, the multi-sector communication system allows thefrequency resources of the sector dedicated band defined from among thesector common band allocated to the user, to be reused as the sectordedicated band in other sectors according to the second DCA scheme. Thatis, the frequency resources of the inter-sector shared band used by theuser are partially returned as the inter-sector shared band only in twoneighboring sectors to which the user is connected.

Referring to FIG. 68, the multi-sector communication system allows thefrequency resources of the sector dedicated band defined from among thesector common band allocated to the user, to be reused as a inter-sectorshared band for a inter-sector boundary region not adjacent to thesector where the user is located according to the first DCA scheme. Thatis, the frequency resources of the inter-sector shared band are fullyreturned, as the inter-sector shared band, from the user in all thesectors.

Referring to FIG. 69, the multi-sector communication system allows thefrequency resources of the sector dedicated band defined from among thesector common band allocated to the user, to be reused as a inter-sectorshared band for a inter-sector boundary region not adjacent to thesector where the user is located according to the second DCA scheme.That is, the frequency resources of the inter-sector shared band arepartially returned, as the inter-sector shared band, from the user inonly two neighboring sectors to which the user is connected.

Accordingly, when the user moves from the inter-sector boundary regionto the sector central region, the multi-sector communication systemimmediately performs a DCA procedure to define the sector dedicated bandin the sector common band, allocate the same to the user, and have theinter-sector shared band in use returned from the user. Or, when theuser stays in the sector central region for a predetermined period oftime or lacks the frequency resources of the inter-sector shared bandwhile using the current frequency resources of the inter-sector sharedband, the multi-sector communication system performs a DCA procedure todefine the sector dedicated band in the sector common band, allocate thesame to the user, and have the inter-sector shared band in use returnedfrom the user.

FIG. 70 and 71 illustrates an example in which DCA is performed when auser moves from a inter-sector boundary region to a sector centralregion in a multi-sector communication system according to an exemplaryembodiment of the present invention. In FIG. 70 and 71, the multi-sectorcommunication system allocates the sector dedicated band to a user whois currently using the inter-sector shared band defined from among thesector common band, and returns frequency resources defined as theinter-sector shared band in the sector common band, as the sector commonband.

Referring to FIG. 70, the multi-sector communication system fullyreturns the frequency resources of the inter-sector shared band definedfrom among the sector common band used by the user, as the sector commonband, in all the sectors according to the first DCA scheme.

Referring to FIG. 71, the multi-sector communication system partiallyreturns the frequency resources of the inter-sector shared band definedfrom among the sector common band used by the user in only twoneighboring sectors to which the user is connected, as the sector commonband, according to the second DCA scheme.

Accordingly, when the user moves from the inter-sector boundary regionto the sector central region, the multi-sector communication systemimmediately performs a DCA procedure to allocate the sector dedicatedband to the user and have the inter-sector shared band defined fromamong the sector common band returned from the user. Or, when the userstays in the sector central region for a predetermined period of time orlacks the frequency resources of the sector common band while continuingto use the frequency resources of the inter-sector shared band definedfrom among the sector common band, the multi-sector communication systemperforms a DCA procedure to allocate the sector dedicated band to theuser and have the inter-sector shared band defined from among the sectorcommon band returned from the user.

FIG. 72 and 73 illustrates an example in which DCA is performed when auser moves from a inter-sector boundary region to a sector centralregion in a multi-sector communication system according to an exemplaryembodiment of the present invention. In FIG. 72 and 73, the multi-sectorcommunication system allocates a sector dedicated band to a user who iscurrently using the inter-sector shared band defined from among thesector dedicated band.

Referring to FIG. 72, the multi-sector communication system defines thefrequency resources of the inter-sector shared band defined from amongthe sector dedicated band currently used by the user, as the sectordedicated band, so that the user continues to use the same. Accordingly,when the user moves from the inter-sector boundary region to the sectorcentral region, the multi-sector communication system immediatelyperforms a DCA procedure to redefine the inter-sector shared banddefined from among the sector dedicated band, as the sector dedicatedband, in the sector where the user is located so that the user continuesto use the frequency resources. Or, when the user stays in the sectorcentral region for a predetermined period of time or lacks the frequencyresources of the sector dedicated band while using the current frequencyresources of the inter-sector shared band, the multi-sectorcommunication system performs a DCA procedure to redefine theinter-sector shared band defined from among the sector dedicated band,as the sector dedicated band, in the sector where the user is located sothat the user continues to use the frequency resources.

Referring to FIG. 73, the multi-sector communication system definesdifferent frequency resources from the frequency resources of theinter-sector shared band defined from among the sector dedicated bandcurrently used by the user, as the sector dedicated band, so that theuser uses the same. In this case, the frequency resources in use arereturned as the sector dedicated band, either fully, according to thefirst DCA scheme, or partially, according to the second DCA scheme.Accordingly, when the user moves from the inter-sector boundary regionto the sector central region, the multi-sector communication systemimmediately performs a DCA procedure to allocate empty frequencyresources in the sector dedicated band to the user in the sector wherethe user is located, and to have the inter-sector shared band definedfrom among the sector dedicated band returned as the sector dedicatedband. Or, when the user stays in the sector central region for apredetermined period of time or lacks the frequency resources of thesector dedicated band while using the current frequency resources of theinter-sector shared band, the multi-sector communication system performsa DCA procedure to allocate empty frequency resources in the sectordedicated band to the user in the sector where the user is located andhave the inter-sector shared band defined from among the sectordedicated band returned from the user, as the sector dedicated band.

FIG. 74 and 75 illustrates an example in which DCA is performed when auser moves from a inter-sector boundary region to a sector centralregion in a multi-sector communication system according to an exemplaryembodiment of the present invention. In FIG. 74 and 75, the multi-sectorcommunication system defines a sector dedicated band from among ainter-sector shared band and allocates the same to a user who iscurrently using the inter-sector shared band.

Referring to FIG. 74, the multi-sector communication system defines thefrequency resources of the inter-sector shared band currently used bythe user, as a sector dedicated band so that the user continues to usethe frequency resources. Accordingly, when the user moves from theinter-sector boundary region to the sector central region, themulti-sector communication system immediately performs a DCA procedureto redefine frequency resources of the inter-sector shared band that arebeing used by the user, as the sector dedicated band, in the sectorwhere the user is located, so that the user continues to use thefrequency resources. Or, when the user stays in the sector centralregion for a predetermined period of time or lacks the frequencyresources of the inter-sector shared band while using the currentfrequency resources of the inter-sector shared band, the multi-sectorcommunication system performs a DCA procedure to redefine frequencyresources of the inter-sector shared band that is being used by theuser, as the sector dedicated band, in the sector where the user islocated, so that the user continues to use the frequency resources.

Referring to FIG. 75, the multi-sector communication system definesdifferent frequency resources from the frequency resources of theinter-sector shared band currently used by the user, as the sectordedicated band, so that the user uses the same. In this case, thefrequency resources in use are fully returned as the inter-sector sharedband according to the first DCA scheme or partially returned as theinter-sector shared band according to the second DCA scheme.Accordingly, when the user moves from the inter-sector boundary regionto the sector central region, the multi-sector communication systemimmediately performs a DCA procedure to define empty frequency resourcesin the inter-sector shared band, as the sector dedicated band, in thesector where the user is located, allocate the same to the user, andhave the inter-sector shared band in use returned from the user. Or,when the user stays in the sector central region for a predeterminedperiod of time or lacks the frequency resources of the inter-sectorshared band while using the current frequency resources of theinter-sector shared band, the multi-sector communication system performsa DCA procedure to define empty frequency resources in the inter-sectorshared band, as the sector dedicated band, in the sector where the useris located, allocate the same to the user, and have the inter-sectorshared band returned from the user.

FIGS. 76 to 79 illustrates an example in which DCA is performed when auser moves from a inter-sector boundary region to a sector centralregion in a multi-sector communication system according to an exemplaryembodiment of the present invention. In FIGS. 76 to 79, the multi-sectorcommunication system defines the sector dedicated band from among thesector common band and allocates the same to a user who is currentlyusing the inter-sector shared band defined from among the sector commonband.

Referring to FIG. 76, the multi-sector communication system redefinesthe frequency resources of the inter-sector shared band, as sectordedicated band, in the sector common band currently used by the user sothat the user continues to use the frequency resources. Also, themulti-sector communication system allows the sector dedicated banddefined from among the sector common band allocated to the user, to bereused as the sector dedicated band in other sectors. Accordingly, whenthe user moves from the inter-sector boundary region to the sectorcentral region, the multi-sector communication system immediatelyperforms a DCA procedure to redefine frequency resources of theinter-sector shared band defined from among the sector common band usedby the user, as the sector dedicated band, in the sector where the useris located so that the user continues to use the frequency resources.Or, when the user stays in the sector central region for a predeterminedperiod of time or lacks the frequency resources of the sector commonband while continuing to use the frequency resources of the inter-sectorshared band defined from among the sector common band, the multi-sectorcommunication system performs a DCA procedure to redefine frequencyresources of the inter-sector shared band defined from among the sectorcommon band used by the user, as the sector dedicated band, in thesector where the user is located, so that the user continues to use thefrequency resources.

Referring to FIG. 77, the multi-sector communication system redefinesthe frequency resources of the inter-sector shared band, as the sectordedicated band, in the sector common band currently used by the user sothat the user continues to use the frequency resources. Also, themulti-sector communication system allows the sector dedicated banddefined from among the sector common band allocated to the user, to bereused as a inter-sector shared band for a inter-sector boundary regionnot adjacent to the sector where the user is located. Accordingly, whenthe user moves from the inter-sector boundary region to the sectorcentral region, the multi-sector communication system immediatelyperforms a DCA procedure to redefine frequency resources of theinter-sector shared band defined from among the sector common band usedby the user, as the sector dedicated band, in the sector where the useris located so that the user continues to use the frequency resources.Or, when the user stays in the sector central region for a predeterminedperiod of time or lacks the frequency resources of the sector commonband while continuing to use the frequency resources of the inter-sectorshared band defined from among the sector common band, the multi-sectorcommunication system performs a DCA procedure to redefine frequencyresources of the inter-sector shared band defined from among the sectorcommon band used by the user, as the sector dedicated band, in thesector where the user is located, so that the user continues to use thefrequency resources.

Referring to FIG. 78, the multi-sector communication system defines thefrequency resources of the sector common band different from thefrequency resources of the inter-sector shared band defined from amongthe sector common band currently used by the user, as the sectordedicated band, so that the user uses the same. In this case, thefrequency resources in use are fully returned as the sector common bandaccording to the first DCA scheme or partially returned as the sectorcommon band according to the second DCA scheme. Also, the multi-sectorcommunication system allows the sector dedicated band defined from amongthe sector common band allocated to the user, to be reused as the sectordedicated band in other sectors. Accordingly, when the user moves fromthe inter-sector boundary region to the sector central region, themulti-sector communication system immediately performs a DCA procedureto define empty frequency resources in the sector common band, as thesector dedicated band, in the sector where the user is located, allocatethe same to the user, and have the inter-sector shared band defined fromamong the sector common band returned as the sector common band. Or,when the user stays in the sector central region for a predeterminedperiod of time or lacks the frequency resources of the sector commonband while continuing to use the frequency resources of the inter-sectorshared band defined from among the sector common band, the multi-sectorcommunication system performs a DCA procedure to define empty frequencyresources in the sector common band, as the sector dedicated band, inthe sector where the user is located, allocate the same to the user, andhave the inter-sector shared band defined from among the sector commonband returned as the sector common band.

Referring to FIG. 79, the multi-sector communication system defines thefrequency resources of the sector common band different from thefrequency resources of the inter-sector shared band defined from amongthe sector common band currently used by the user, as the sectordedicated band, so that the user uses the same. In this case, thefrequency resources in use are fully returned as the sector common bandaccording to the first DCA scheme or partially returned as the commonband according to the second DCA scheme sector. Also, the multi-sectorcommunication system allows the sector dedicated band defined from amongthe sector common band allocated to the user, to be reused as ainter-sector shared band for a inter-sector boundary region not adjacentto the sector where the user is located. Accordingly, when the usermoves from the inter-sector boundary region to the sector centralregion, the multi-sector communication system immediately performs a DCAprocedure to define empty frequency resources in the sector common band,as the sector dedicated band, in the sector where the user is located,allocate the same to the user, and have the inter-sector shared banddefined from among the sector common band returned as the sector commonband. Or, when the user stays in the sector central region for apredetermined period of time or lacks the frequency resources of thesector common band while continuing to use the frequency resource of theinter-sector shared band defined from among the sector common band, themulti-sector communication system performs a DCA procedure to defineempty frequency resources in the sector common band, as the sectordedicated band, in the sector where the user is located, allocate thesame to the user, and have the inter-sector shared band defined fromamong the sector common band returned as the sector common band. Anexample in which DCA is performed when a user moves from a sectorcentral region to a inter-sector boundary region will now be described.

FIGS. 80 to 89 illustrates an example in which DCA is performed when auser moves from a sector central region to a inter-sector boundaryregion in a multi-sector communication system according to an exemplaryembodiment of the present invention.

Referring to FIG. 80, the multi-sector communication system allocates ainter-sector shared band to a user who is currently using the sectordedicated band, and has the sector dedicated band returned from theuser. Accordingly, when the user moves from the sector central region tothe inter-sector boundary region, the multi-sector communication systemimmediately performs a DCA procedure to allocate the inter-sector sharedband to the user and have the sector dedicated band returned from theuser.

Referring to FIG. 81, the multi-sector communication system defines theinter-sector shared band from among the sector common band, allocatesthe same to a user who is currently using the sector dedicated band, andhas the sector dedicated band returned from the user. Accordingly, whenthe user moves from the sector central region to the inter-sectorboundary region, the multi-sector communication system immediatelyperforms a DCA procedure to define the inter-sector shared band in thesector common band, allocate the same to the user, and have the sectordedicated band returned from the user.

Referring to FIG. 82, the multi-sector communication system allocatesthe inter-sector shared band to a user who is currently using the sectordedicated band defined from among the sector common band, and hasfrequency resources in use returned, as the sector common band, from theuser. Also, the multi-sector communication system allows the frequencyresources of the sector dedicated band defined from among the sectorcommon band allocated to the user, to be reused as a sector dedicatedband in other sectors. In this case, frequency resources of the sectordedicated band defined from among the sector common band used by theuser are fully returned as the sector common band in all the sectorsaccording to the first DCA scheme. Accordingly, when the user moves fromthe sector central region to the inter-sector boundary region, themulti-sector communication system immediately performs a DCA procedureto allocate the inter-sector shared band to the user and have the sectordedicated band defined from among the sector common band returned, asthe sector common band, from the user.

Referring to FIG. 83, the multi-sector communication system allocatesthe inter-sector shared band to a user who is currently using the sectordedicated band defined from among the sector common band, and hasfrequency resources in use returned, as the sector common band, from theuser. Also, the multi-sector communication system allows the frequencyresources of the sector dedicated band defined from among the sectorcommon band allocated to the user, to be reused as the sector dedicatedband in other sectors. In this case, frequency resources of the sectordedicated band defined from among the sector common band used by theuser are partially returned as the sector common band according to thesecond DCA scheme only in a sector to which the user is connected.Accordingly, when the user moves from the sector central region to theinter-sector boundary region, the multi-sector communication systemimmediately performs a DCA procedure to allocate the inter-sector sharedband to the user and have the sector dedicated band defined from amongthe sector common band returned, as the sector common band, from theuser.

Referring to FIG. 84, the multi-sector communication system allocatesthe inter-sector shared band to a user who is currently using the sectordedicated band defined from among the sector common band, and hasfrequency resources in use returned, as the sector common band, from theuser. Also, the multi-sector communication system allows the frequencyresources of the sector dedicated band defined from among the sectorcommon band allocated to the user, to be reused as a inter-sector sharedband for a inter-sector boundary region not adjacent to the sector wherethe user is located. In this case, frequency resources of the sectordedicated band defined from among the sector common band used by theuser are fully returned as the sector common band in all the sectorsaccording to the first DCA scheme. Accordingly, when the user moves fromthe sector central region to the inter-sector boundary region, themulti-sector communication system immediately performs a DCA procedureto allocate the inter-sector shared band to the user and have the sectordedicated band defined from among the sector common band returned, asthe sector common band, from the user.

Referring to FIG. 85, the multi-sector communication system allocatesthe inter-sector shared band to a user who is currently using the sectordedicated band defined from among the sector common band, and hasfrequency resources in use returned, as the sector common band, from theuser. Also, the multi-sector communication system allows the frequencyresources of the sector dedicated band defined from among the sectorcommon band allocated to the user, to be reused as a inter-sector sharedband for a inter-sector boundary region not adjacent to the sector wherethe user is located. In this case, frequency resources of the sectordedicated band defined from among the sector common band used by theuser are partially returned as the sector common band only in a sectorto which the user is connected. Accordingly, when the user moves fromthe sector central region to the inter-sector boundary region, themulti-sector communication system immediately performs a DCA procedureto allocate the inter-sector shared band to the user and have the sectordedicated band defined from among the sector common band returned, asthe sector common band, from the user.

Referring to FIG. 86, the multi-sector communication system defines theinter-sector shared band from among the sector dedicated band andallocates the same to a user who is currently using the sector dedicatedband. Also, the multi-sector communication system redefines thefrequency resources of the sector dedicated band currently used by theuser, as the inter-sector shared band so that the user continues to usethe frequency resources. Accordingly, when the user moves from thesector central region to the inter-sector boundary region, themulti-sector communication system immediately performs a DCA procedureto allow the user to continue to use the frequency resources of thededicated band and redefine the same as the inter-sector shared band intwo sectors adjacent to the user. When the frequency resources used bythe user are occupied by other users in neighboring sectors that are notyet connected with the user, the multi-sector communication systemredefines the frequency resources as the inter-sector shared band to beused by the user after allocating another band to the other users.

Although not shown, the multi-sector communication system definesdifferent frequency resources from the frequency resources of the sectordedicated band currently used by the user, as the inter-sector boundaryregion shared so that the user uses the same. In this case, thefrequency resources in use are returned as the sector dedicated bandeither fully, according to the first DCA scheme, or partially, accordingto the second DCA scheme. Accordingly, when the user moves from thesector central region to the inter-sector boundary region, themulti-sector communication system immediately performs a DCA procedureto define a band in the sector dedicated empty band in common to twosectors adjacent to the user, as the inter-sector shared band, allocatethe same to the user who is using the sector dedicated band, and havethe sector dedicated band returned from the user. If there is no emptyband in common to the two sectors adjacent to the user, the multi-sectorcommunication system allocates another frequency band to a user locatedin the sector central region or the inter-sector boundary region toprepare the empty band in common to the two sectors adjacent to theuser, defines the band as the inter-sector shared band, and allocatesthe inter-sector shared band to the user.

Referring to FIG. 87, the multi-sector communication system allocatesthe inter-sector shared band to a user who is currently using the sectordedicated band defined from among the inter-sector shared band. Also,the multi-sector communication system redefines the frequency resourcesof the sector dedicated band defined from among the inter-sector sharedband currently used by the user, as the inter-sector shared band so thatthe user continues to use the frequency resources. Accordingly, when theuser moves from the sector central region to the inter-sector boundaryregion, the multi-sector communication system immediately performs a DCAprocedure to allow the user to continue to use the frequency resourcesof the dedicated band defined from among the inter-sector shared bandsector and redefine the frequency resources as the inter-sector sharedband in two sectors adjacent to the user to be used by the user. If thefrequency resources used by the user are occupied by other users inneighboring sectors that are not yet connected with the user, themulti-sector communication system redefines the frequency resources asthe inter-sector shared band to be used by the user, after allocatinganother band to the other users.

Although not shown, the multi-sector communication system allows theuser to use frequency resources of the inter-sector shared banddifferent from the frequency resources of the sector dedicated banddefined from among the inter-sector shared band currently used by theuser. In this case, the frequency resources in use are fully returned asthe inter-sector shared band according to the first DCA scheme orpartially returned as the inter-sector shared band according to thesecond DCA scheme. Accordingly, when the user moves from the sectorcentral region to the inter-sector boundary region, the multi-sectorcommunication system immediately performs a DCA procedure to allocate aband in the inter-sector boundary region shared empty band in common totwo sectors adjacent to the user, to the user who is using the sectordedicated band defined from among the inter-sector shared band, and tohave the sector dedicated band defined from among the inter-sectorshared band returned from the user. If there is no empty band in commonto the two sectors adjacent to the user, the multi-sector communicationsystem allocates another other frequency band to a user located in thesector central region or the inter-sector boundary region to prepare theempty band in common to the two sectors adjacent to the user, definesthe band as the inter-sector shared band, and allocates the same to theuser.

Referring to FIG. 88, the multi-sector communication system defines theinter-sector shared band from among the sector common band and allocatesthe same to a user who is currently using the sector dedicated banddefined from among the sector common band. Also, the multi-sectorcommunication system redefines frequency resources of the sectordedicated band defined from among the sector common band currently usedby the user, as the inter-sector shared band so that the user continuesto use the frequency resources. In this case, the multi-sectorcommunication system allows the sector dedicated band defined from amongthe sector common band allocated to the user, to be reused as a sectordedicated band in other sectors. Accordingly, when the user moves fromthe sector central region to the inter-sector boundary region, themulti-sector communication system immediately performs a DCA procedureto allow the user to continue to use the frequency resources of thesector dedicated band defined from among the sector common band andredefine the frequency resources as the inter-sector shared band in twosectors adjacent to the user to be used by the user. If the frequencyresources used by the user are occupied by other users in neighboringsectors that are not yet connected with the user, the multi-sectorcommunication system redefines the frequency resources as theinter-sector shared band to be used by the user after allocating anotherband to the other users.

Referring to FIG. 89, the multi-sector communication system defines theinter-sector shared band from among the sector common band and allocatesthe same to a user who is currently using the sector dedicated banddefined from among the sector common band. Also, the multi-sectorcommunication system redefines frequency resources of the sectordedicated band defined from among the sector common band currently usedby the user, as the inter-sector shared band so that the user continuesto use the frequency resources. In this case, the multi-sectorcommunication system allows the sector dedicated band defined from amongthe sector common band allocated to the user, to be reused as ainter-sector shared band for a inter-sector boundary region not adjacentto the sector where the user is located. Accordingly, when the usermoves from the sector central region to the inter-sector boundaryregion, the multi-sector communication system immediately performs a DCAprocedure to allow the user to continue to use the frequency resourcesof the sector dedicated band defined from among the sector common bandand redefine the frequency resources as the inter-sector shared band intwo sectors adjacent to the user to be used by the user. If thefrequency resources used by the user are occupied by other users inneighboring sectors that are not yet connected with the user, themulti-sector communication system redefines the frequency resources asthe inter-sector shared band to be used by the user, after allocatinganother band to the other users.

Although not shown, the multi-sector communication defines systemfrequency resources different from the frequency resources of the sectordedicated band defined from among the sector common band currently usedby the user, as the inter-sector shared band, so that the user uses thesame. In this case, the frequency resources in use are returned as thesector common band fully according to the first DCA scheme or partiallyaccording to the second DCA scheme. Accordingly, when the user movesfrom the sector central region to the inter-sector boundary region, themulti-sector communication system immediately performs a DCA procedureto define an empty band in common to two sectors adjacent to the user,as the inter-sector shared band, allocate the same to the user who isusing the sector dedicated band defined from among the sector commonband, and have the sector dedicated band defined from among the commonband in use returned from the user. If there is no empty band in commonto the two sectors adjacent to the user, the multi-sector communicationsystem allocates another frequency band to a user located in the sectorcentral region or the inter-sector boundary region to prepare the emptyband in common to the two sectors adjacent to the user, defines the bandas the inter-sector shared band, and allocates the same to the user. Anexample in which DCA is performed when a user moves from a inter-sectorboundary region to a cell central region will be described.

FIGS. 90 to 97 illustrates an example in which DCA is performed when auser moves from a inter-sector boundary region to a cell central regionin a multi-sector communication system according to an exemplaryembodiment of the present invention.

Referring to FIG. 90, the multi-sector communication system allocatesthe sector common band to a user who is currently using the inter-sectorshared band, and has the inter-sector shared band in use returned fromthe user. In this case, the inter-sector shared band used by the user isfully returned according to the first DCA scheme. Accordingly, when theuser moves from the inter-sector boundary region to the cell centralregion, the multi-sector communication system immediately performs a DCAprocedure to allocate the sector common band to the user and have theinter-sector shared band returned from the user. When the user stays inthe cell central region for a predetermined period of time or lacks thefrequency resources of the inter-sector shared band while using thecurrent frequency resources of the inter-sector shared band, themulti-sector communication system performs a DCA procedure to allocatethe sector common band to the user and have the inter-sector shared bandreturned from the user.

Referring to FIG. 91, the multi-sector communication system allocatesthe sector common band to a user who is currently using the inter-sectorshared band, and has the inter-sector shared band in use returned fromthe user. In this case, the inter-sector shared band in used by the useris partially returned from the user according to the second DCA scheme.Accordingly, when the user moves from inter-sector boundary region tothe cell central region, the multi-sector communication systemimmediately performs a DCA procedure to allocate the sector common bandto the user and have the inter-sector shared band returned from theuser. Or, when the user stays in the cell central region for apredetermined period of time or lacks the frequency resources of theinter-sector shared band while using the current frequency resources ofthe inter-sector shared band, the multi-sector communication systemperforms a DCA procedure to allocate the sector common band to the userand have the inter-sector shared band returned from the user.

Referring to FIG. 92, the multi-sector communication system defines thesector common band from among the sector dedicated band, allocates thesame to a user who is currently using the inter-sector shared band, andhas the inter-sector shared band in use returned from the user. In thiscase, the inter-sector shared band used by the user is fully returnedaccording to the first DCA scheme. Accordingly, when the user moves frominter-sector boundary region to the cell central region, themulti-sector communication system immediately performs a DCA procedureto define the sector common band in the sector dedicated band, allocatethe same to the user, and have the inter-sector shared band in usereturned from the user. Or, when the user stays in the cell centralregion for a predetermined period of time or lacks the frequencyresources of the inter-sector shared band while using the currentfrequency resources of the inter-sector shared band, the multi-sectorcommunication system performs a DCA procedure to define the sectorcommon band in the sector dedicated band, allocate the same to the user,and have the inter-sector shared band returned from the user.

Referring to FIG. 93, the multi-sector communication system defines thesector common band from among the sector dedicated band, allocates thesame to a user who is currently using the inter-sector shared band, andhas the inter-sector shared band in use returned from the user. In thiscase, the inter-sector shared band used by the user is partiallyreturned according to the first DCA scheme. Accordingly, when the usermoves from inter-sector boundary region to the cell central region, themulti-sector communication system immediately performs a DCA procedureto define the sector common band in the sector dedicated band, allocatethe same to the user, and have the inter-sector shared band in usereturned from the user. Or, when the user stays in the cell centralregion for a predetermined period of time or lacks the frequencyresources of the inter-sector shared band while using the currentfrequency resources of the inter-sector shared band, the multi-sectorcommunication system performs a DCA procedure to define the sectorcommon band in the sector dedicated band, allocate the same to the user,and have the inter-sector shared band returned from the user.

Referring to FIG. 94, the multi-sector communication system allocatesthe sector common band to a user who is currently using the inter-sectorshared band defined from among the sector dedicated band, and has thefrequency resources in use returned as the sector dedicated band.Accordingly, when the user moves from inter-sector boundary region tothe cell central region, the multi-sector communication systemimmediately performs a DCA procedure to allocate the sector common bandto the user and have the inter-sector shared band defined from among thesector dedicated band in use returned from the user. Or, when the userstays in the cell central region for a predetermined period of time orlacks the frequency resources of the sector dedicated band whilecontinuing to use the frequency resources of the inter-sector sharedband defined from among the sector dedicated band, the multi-sectorcommunication system performs a DCA procedure to allocate the sectorcommon band to the user and have the inter-sector shared band definedfrom among the sector dedicated band returned from the user.

Referring to FIG. 95, the multi-sector communication system defines thesector common band from among the sector dedicated band, and allocatesthe same to a user who is currently using the inter-sector shared banddefined from among the sector dedicated band. Also, the multi-sectorcommunication system redefines the frequency resources of theinter-sector shared band defined from among the sector dedicated bandcurrently used by the user, as the sector common band, so that the usercontinues to use the frequency resources. Accordingly, when the usermoves from the inter-sector boundary region to the cell central region,the multi-sector communication system immediately performs a DCAprocedure to allow the user to continue to use the frequency resourcesof the inter-sector shared band defined from among the sector dedicatedband and allow the same to be redefined as the sector common band in allthe sectors. When the frequency resources used by the user are occupiedby other users in remaining sectors that are not yet connected with theuser, the multi-sector communication system redefines the frequencyresources as the sector common band to be used by the user afterallocating another band to the users. Also, when the user stays in thecell central region for a predetermined period of time or lacks thefrequency resources of the sector dedicated band while continuing to usethe frequency resources of the inter-sector shared band defined fromamong the sector dedicated band upon movement from inter-sector boundaryregion to the cell central region, the multi-sector communication systemperforms a DCA procedure to allow the user to continue to use thefrequency resources of the inter-sector shared band defined from amongthe sector dedicated band and allow the same to be redefined as thesector common band in all the sectors. When the frequency resources usedby the user are occupied by other users in remaining sectors that arenot yet connected with the user, the multi-sector communication systemredefines the frequency resources as the sector common band to be usedby the user after allocating another band to the users.

Although not shown, the multi-sector communication system definesdifferent frequency resources from the frequency resources of theinter-sector shared band defined from among the sector dedicated bandcurrently used by the user, as the sector common band, so that the useruses the same. In this case, the frequency resources in use are returnedas the sector dedicated band either fully, according to the first DCAscheme, or partially, according to the second DCA scheme. Accordingly,when the user moves from inter-sector boundary region to the cellcentral region, the multi-sector communication system immediatelyperforms a DCA procedure to define an empty band in common to all thesectors, as the sector common band, allocate the same to the user who isusing the inter-sector shared band defined from among the sectordedicated band, and have the inter-sector shared band defined from amongthe sector dedicated band returned from the user. If there is no emptyband in common to all the sectors, the multi-sector communication systemallocates another frequency band to a user located in the sector centralregion or the inter-sector boundary region to prepare the empty band incommon to all the sectors, defines the frequency resources as the sectorcommon band, and allocates the same to the user. Also, when the userstays in the cell central region for a predetermined period of time orlacks the frequency resources of the sector dedicated band whilecontinuing to use the frequency resources of the inter-sector sharedband defined from among the sector dedicated band upon movement frominter-sector boundary region to the cell central region, themulti-sector communication system performs a DCA procedure to define anempty band in common to all the sectors, as the sector common band,allocate the same to the user who is using the inter-sector shared banddefined from among the sector dedicated band, and have the inter-sectorshared band defined from among the sector dedicated band returned fromthe user. If there is no empty band in common to all the sectors, themulti-sector communication system allocates another frequency band to auser located in the sector central region or the inter-sector boundaryregion to prepare the empty band in common to all the sectors, definesthe frequency resources as the sector common band, and allocates thesame to the user.

Referring to FIG. 96, the multi-sector communication system defines thesector common band and allocates the same to a user who is currentlyusing the inter-sector shared band in the inter-sector shared band.Also, the multi-sector communication system redefines the frequencyresources of the inter-sector shared band currently used by the user, asthe sector common band, so that the user continues to use the frequencyresources. Accordingly, when the user moves from inter-sector boundaryregion to the cell central region, the multi-sector communication systemimmediately performs a DCA procedure to allow the user to continue touse the frequency resources of the inter-sector shared band and allowthe same to be redefined as the sector common band in all the sectors.When the frequency resources used by the user are occupied by otherusers in remaining sectors that are not yet connected with the user, themulti-sector communication system redefines the frequency resources asthe sector common band to be used by the user after allocating anotherband to the users. Also, when the user stays in the cell central regionfor a predetermined period of time or lacks the frequency resources ofthe inter-sector shared band while using the current frequency resourcesof the inter-sector shared band upon movement from the inter-sectorboundary region to the cell central region, the multi-sectorcommunication system performs a DCA procedure to allow the user tocontinue to use the frequency resources of the inter-sector shared bandand allow the same to be redefined as the sector common band in all thesectors. When the frequency resources used by the user are occupied byother users in remaining sectors that are not yet connected with theuser, the multi-sector communication system redefines the frequencyresources as the sector common band to be used by the user afterallocating another band to the users.

Although not shown, the multi-sector communication system definesdifferent frequency resources from the frequency resources of theinter-sector shared band currently used by the user, as the sectorcommon band, so that the user uses the same. In this case, the frequencyresources in use are returned as the inter-sector shared band eitherfully, according to the first DCA scheme, or partially, according to thesecond DCA scheme. Accordingly, when the user moves from theinter-sector boundary region to the cell central region, themulti-sector communication system immediately performs a DCA procedureto define an empty band in common to all the sectors, as the sectorcommon band, allocate the same to the user that is using theinter-sector shared band, and have the inter-sector shared band returnedfrom the user. If there is no empty band in common to all the sectors,the multi-sector communication system allocates another frequency bandto a user located in the sector central region or the inter-sectorboundary region to prepare the empty band in common to all the sectors,defines the frequency resources as the sector common band, and allocatesthe same to the user. Also, when the user stays in the cell centralregion for a predetermined period of time or lacks the frequencyresources of the inter-sector shared band while using the currentfrequency resources of the inter-sector shared band upon movement fromthe inter-sector boundary region to the cell central region, themulti-sector communication system performs a DCA procedure to define asempty band in common to all the sectors, as the sector common band,allocate the same to the user that is using the inter-sector sharedband, and have the inter-sector shared band returned from the user. Ifthere is no empty band in common to all the sectors, the multi-sectorcommunication system allocates another frequency band to a user locatedin the sector central region or the inter-sector boundary region toprepare the empty band in common to all the sectors, defines thefrequency resources as the sector common band, and allocates the same tothe user.

Referring to FIG. 97, the multi-sector communication system allocatesthe sector common band to a user who is currently using the inter-sectorshared band defined from among the sector common band. Also, thefrequency resources of the inter-sector shared band defined from amongthe sector common band currently used by the user are redefined as thesector common band, so that the user continues to use the frequencyresources. Accordingly, when the user moves from the inter-sectorboundary region to the cell central region, the multi-sectorcommunication system immediately performs a DCA procedure to allow theuser to continue to use the frequency resources of the inter-sectorshared band defined from among the sector common band and allow the sameto be redefined as the sector common band in all the sectors. When thefrequency resources used by the user are occupied by other users inremaining sectors that are not yet connected with the user, themulti-sector communication system redefines the frequency resources asthe sector common band to be used by the user after allocating anotherband to the users. Also, when a user stays in the cell central regionfor a predetermined period of time and lacks the frequency resources ofthe sector common band while continuing to use the frequency resourcesof the inter-sector shared band defined from among the sector commonband upon movement from the inter-sector boundary region to the cellcentral region, the multi-sector communication system performs a DCAprocedure to allow the user to continue to use the frequency resourcesof the inter-sector shared band defined from among the sector commonband and allow the same to be redefined as the sector common band in allthe sectors. When the frequency resources used by the user are occupiedby other users in remaining sectors that are not yet connected with theuser, the multi-sector communication system redefines the frequencyresources as the sector common band to be used by the user afterallocating another band to the users.

Although not shown, the multi-sector communication system may definefrequency resources different from the frequency resources of theinter-sector shared band defined from among the sector common bandcurrently used by the user, as the sector common band. In this case, thefrequency resources in use are returned as the sector common band eitherfully, according to the first DCA scheme, or partially, according to thesecond DCA scheme. Accordingly, when the user moves from theinter-sector boundary region to the cell central region, themulti-sector communication system immediately performs a DCA procedureto define an empty band in common to all the sectors, as the sectorcommon band, allocate the same to the user that is using theinter-sector shared band defined from among the sector common band, andhave the inter-sector shared band defined from among the sector commonband returned from the user. If there is no empty band in common to allsectors, the multi-sector communication system allocates anotherfrequency band to a user located in the sector central region or theinter-sector boundary region to prepare the empty band in common to allthe sectors, defines the frequency resources as the sector common band,and allocates the same to the user. Also, when a user stays in the cellcentral region for a predetermined period of time or lacks the frequencyresources of the sector common band while continuing to use thefrequency resources of the inter-sector shared band defined from amongthe sector common band upon movement from the inter-sector boundaryregion to the cell central region, the multi-sector communication systemperforms a DCA procedure to define an empty band in common to all thesectors, as the sector common band, allocate the same to the user thatis using the inter-sector shared band defined from among the sectorcommon band, and have the inter-sector shared band defined from amongthe sector common band returned from the user. If there is no empty bandin common to all the sectors, the multi-sector communication systemallocates another frequency band to a user located in the sector centralregion or the inter-sector boundary region to prepare the empty band incommon to all the sectors, defines the frequency resource as the sectorcommon band, and allocates the same to the user. An example in which DCAis performed when a user moves from a cell central region to ainter-sector boundary region will now be described.

FIGS. 98 to 103 illustrates an example in which DCA is performed when auser moves from a cell central region to a inter-sector boundary regionin a multi-sector communication system according to an exemplaryembodiment of the present invention.

Referring to FIG. 98, the multi-sector communication system allocates ainter-sector shared band to a user who is currently using the sectorcommon band and has the sector common band returned from the user.Accordingly, when the user moves from the cell central region to theinter-sector boundary region, the multi-sector communication systemimmediately performs a DCA procedure to allocate the inter-sector sharedband to the user, and have the sector common band in use returned fromthe user. Or, when a user stays in the inter-sector boundary region fora predetermined period of time or lacks the frequency resources of thesector common band while continuing to use the frequency resources ofthe sector common band, the multi-sector communication system performs aDCA procedure to allocate the inter-sector shared band to the user andhave the sector common band returned from the user.

Referring to FIG. 99, the multi-sector communication system defines theinter-sector shared band from among the sector dedicated band, allocatesthe same to a user who is currently using the sector common band, andhas the sector common band returned from the user. Accordingly, when theuser moves from the cell central region to the inter-sector boundaryregion, the multi-sector communication system immediately performs a DCAprocedure to define the inter-sector shared band in the sector dedicatedband, allocate the same to the user, and have the sector common band inuse returned from the user. Or, when a user stays in the inter-sectorboundary region for a predetermined period of time or lacks thefrequency resources of the sector common band while continuing to usethe frequency resources of the sector common band, the multi-sectorcommunication system performs a DCA procedure to define the inter-sectorshared band in the sector dedicated band, allocate the same to the user,and have the sector common band in use returned from the user.

Referring to FIG. 100, the multi-sector communication system allocatesthe inter-sector shared band to a user who is currently using the sectorcommon band defined from among the sector dedicated band, and has thefrequency resources in use returned as the sector dedicated band.Accordingly, when the user moves from the cell central region to theinter-sector boundary region, the multi-sector communication systemimmediately performs a DCA procedure to define the inter-sector sharedband, allocate the same to the user, and have the sector common banddefined from among the sector dedicated band returned from the user. Or,when a user stays in the inter-sector boundary region for apredetermined period of time or lacks the frequency resources of thesector dedicated band while continuing to use the frequency resources ofthe sector common band defined from among the sector dedicated band, themulti-sector communication system performs a DCA procedure to allocatethe inter-sector shared band to the user and have the sector common banddefined from among the sector dedicated band in use returned from theuser.

Referring to FIG. 101, the multi-sector communication system defines theinter-sector shared band from among the sector dedicated band andallocates the same to a user who is currently using the sector commonband defined from among the sector dedicated band. Also, themulti-sector communication system redefines the frequency resources ofthe sector common band defined from among the sector dedicated bandcurrently used by the user, as the inter-sector shared band, so that theuser continues to use the frequency resources. Accordingly, when theuser moves from the cell central region to the inter-sector boundaryregion, the multi-sector communication system immediately performs a DCAprocedure to redefine frequency resources of the sector common banddefined from among the sector dedicated band that is used by user, asthe inter-sector shared band in two sectors adjacent to the user, sothat the user continues to use the frequency resources. Or, when a userstays in the inter-sector boundary region for a predetermined period oftime or lacks the frequency resources of the sector dedicated band whilecontinuing to use the frequency resources of the sector common banddefined from among the sector dedicated band, the multi-sectorcommunication system performs a DCA procedure to redefine frequencyresources of the sector common band defined from among the sectordedicated band, as the inter-sector shared band in two sectors adjacentto the user, so that the user continues to use the frequency resources.

Although not shown, the multi-sector communication system defines theinter-sector shared band from among the sector dedicated band andallocates the same to a user who is currently using the sector commonband defined from among the sector dedicated band. Also, themulti-sector communication system defines different frequency resourcesfrom the frequency resources of the sector common band defined fromamong the sector dedicated band currently used by the user, as theinter-sector shared band, so that the user uses the same. In this case,the frequency resources in use are returned as the sector dedicatedband. Accordingly, when the user moves from the cell central region tothe inter-sector boundary region, the multi-sector communication systemimmediately performs a DCA procedure to define a band in the sectordedicated empty band in common to two sectors adjacent to the user, asthe inter-sector shared band, allocate the same to the user who is usingthe sector common band defined from among the sector dedicated band, andhave the sector common band defined from among the sector dedicated bandin use returned from the user. If there is no empty band in common tothe two sectors adjacent to the user, the multi-sector communicationsystem allocates another frequency band to a user located in the sectorcentral region to prepare the empty band in common to the two sectorsadjacent to the user, defines the band as the inter-sector shared band,and allocates the same to the user. Also, when a user stays in theinter-sector boundary region for a predetermined period of time or lacksthe frequency resource of the sector dedicated band while continuing touse the frequency resources of the sector common band defined from amongthe sector dedicated band upon movement from the cell central region tothe inter-sector boundary region, the multi-sector communication systemperforms a DCA procedure to define a band in the sector dedicated emptyband in common to two sectors adjacent to the user, as the inter-sectorshared band, allocate the same to the user who is using the sectorcommon band defined from among the sector dedicated band, and have thesector common band defined from among the sector dedicated band in usereturned from the user. If there is no empty band in common to the twosectors adjacent to the user, the multi-sector communication systemallocates another frequency band to a user located in the sector centralregion to prepare the empty band in common to the two sectors adjacentto the user, defines the band as the inter-sector shared band, andallocates the same to the user.

Referring to FIG. 102, the multi-sector communication system allocatesthe inter-sector shared band to a user that is currently using a sectorcommon band defined from among the inter-sector shared band. Also, themulti-sector communication system redefines the sector common banddefined from among the inter-sector shared band that is currently usedby the user, as the inter-sector shared band, so that the user continuesto use the frequency resources. Accordingly, when the user moves fromthe cell central region to the inter-sector boundary region, themulti-sector communication system immediately performs a DCA procedureto redefine the sector common band defined from among the frequencyresources of the inter-sector shared band that is being used by theuser, as the inter-sector shared band, in two sectors adjacent to theuser, so that the user continues to use the frequency resources. Or,when a user stays in the inter-sector boundary region for apredetermined period of time or lacks the frequency resources of theinter-sector shared band while continuing to use frequency resources ofthe current sector common band defined from among the inter-sectorshared band, the multi-sector communication system performs a DCAprocedure to redefine the sector common band defined from among thefrequency resources of the inter-sector shared band that is being usedby the user, as the inter-sector shared band, in two sectors adjacent tothe user so that the user continues to use the frequency resources.

Although not shown, the multi-sector communication system allocates theinter-sector shared band to a user that is currently using a sectorcommon band defined from among the inter-sector shared band. Also, themulti-sector communication system defines different frequency resourcesfrom the frequency resources of the sector common band defined fromamong the inter-sector shared band that is currently used by the user,as the inter-sector shared band, so that the user uses the same. In thiscase, the frequency resources in use are returned as the inter-sectorshared band. Accordingly, when the user moves from the cell centralregion to the inter-sector boundary region, the multi-sectorcommunication system immediately performs a DCA procedure to allocate aband in the inter-sector boundary region shared empty band in common totwo sectors adjacent to the user to the user, to a user who is using thesector common band defined from among the inter-sector shared band, andhave the sector common band defined from among the inter-sector sharedband returned from the user. If there is no empty band in common to thetwo sectors adjacent to the user, the multi-sector communication systemallocates another frequency band to a user located in the sector centralregion to prepare the empty band in common to the two sectors adjacentto the user, defines the band as the inter-sector shared band, andallocates the same to the user. Also, when a user stays in theinter-sector boundary region for a predetermined period of time or lacksthe frequency resources of the inter-sector shared band while continuingto use frequency resources of the current sector common band definedfrom among the inter-sector shared band upon movement from the cellcentral region to the inter-sector boundary region, the multi-sectorcommunication system performs a DCA procedure to allocate a band in theinter-sector boundary region shared empty band in common to two sectorsadjacent to the user, to the user a sector common band defined fromamong the inter-sector shared band, and have the sector common banddefined from among the inter-sector shared band returned from the user.If there is no empty band in common to the two sectors adjacent to theuser, the multi-sector communication system allocates another frequencyband to a user located in the sector central region to prepare the emptyband in common to the two sectors adjacent to the user, defines the bandas the inter-sector shared band, and allocates the same to the user.

Referring to FIG. 103, the multi-sector communication system defines theinter-sector shared band from among the sector common band and allocatesthe same to a user who is currently using the sector common band. Also,the multi-sector communication system redefines the frequency resourcesof sector common band currently used by the user, as the inter-sectorshared band, so that the user continues to use the frequency resources.Accordingly, when the user moves from the cell central region to theinter-sector boundary region, the multi-sector communication systemimmediately performs a DCA procedure to redefine the frequency resourceof the sector common band used by the user, as the inter-sector sharedband, in two sectors adjacent to the user so that the user continues touse the frequency resources. Or, when a user stays in the inter-sectorboundary region for a predetermined period of time or lacks thefrequency resources of the sector common band while continuing to usethe frequency resources of the sector common band, the multi-sectorcommunication system performs a DCA procedure to redefine frequencyresource of the sector common band used by the user, as the inter-sectorshared band in two sectors adjacent to the user, so that the usercontinues to use the frequency resources.

Although not shown, the multi-sector communication system defines theinter-sector shared band from among the sector common band, andallocates the same to a user who is currently using the sector commonband. Also, the multi-sector communication system defines differentfrequency resources from the frequency resources of sector common bandcurrently used by the user, as the inter-sector shared band. In thiscase, the frequency resources in use are returned as the sector commonband. Accordingly, when the user moves from the cell central region tothe inter-sector boundary region, the multi-sector communication systemimmediately performs a DCA procedure to allocate a band in the sectorcommon empty band in common to two sectors adjacent to the user, to theuser who is using the sector common band, and have the sector commonband in use returned from the user. If there is no empty band in commonto the two sectors adjacent to the user, the multi-sector communicationsystem allocates another frequency band to a user located in the sectorcentral region to prepare the empty band in common to the two sectorsadjacent to the user, defines the band as the inter-sector shared band,and allocates the same to the user. Also, when a user stays in theinter-sector boundary region for a predetermined period of time or lacksthe frequency resources of the sector common band while continuing touse the frequency resources of the sector common band upon movement fromthe cell central region to the inter-sector boundary region, themulti-sector communication system performs a DCA procedure to allocate aband in the sector common empty band in common to two sectors adjacentto the user to the user, to the user who is using the sector commonband, and has the sector common band in use returned from the user. Ifthere is no empty band in common to the two sectors adjacent to theuser, the multi-sector communication system allocates another frequencyband to a user located in the sector central region to prepare the emptyband in common to the two sectors adjacent to the user, defines the bandas the inter-sector shared band, and allocates the same to the user. Anexample in which DCA is performed when a user moves from a sectorcentral region to a cell central region will now be described.

FIGS. 104 to 110 illustrates an example in which DCA is performed when auser moves from a sector central region to a cell central region in amulti-sector communication system according to an exemplary embodimentof the present invention.

Referring to FIG. 104, the multi-sector communication system allocatesthe sector common band to a user who is currently using the sectordedicated band, and has the sector dedicated band returned from theuser. Accordingly, when a user moves from a sector central region to acell central region, the multi-sector communication system immediatelyperforms a DCA procedure to allocate the sector common band to the userand have the sector dedicated band in use returned from the user.

Referring to FIG. 105, the multi-sector communication system defines thesector common band from among the inter-sector shared band, allocatesthe same to a user who is currently using the sector dedicated band, andhas the sector dedicated band returned from the user. Accordingly, whena user moves from a sector central region to a cell central region, themulti-sector communication system immediately performs a DCA procedureto define the sector common band in the inter-sector shared band,allocate the same to the user, and have the sector dedicated bandreturned from the user.

Referring to FIG. 106, the multi-sector communication system allocatesthe sector common band to a user who is currently using the sectordedicated band defined from among the inter-sector shared band, and hasthe frequency resources in use returned as the inter-sector shared bandthrough full return or partial return. Accordingly, when a user movesfrom a sector central region to a cell central region, the multi-sectorcommunication system immediately performs a DCA procedure to allocatethe sector common band to the user and have the sector dedicated banddefined from among the inter-sector shared band returned from the user.

Referring to FIG. 107, the multi-sector communication system defines thesector common band from among the sector dedicated band, and allocatesthe same to a user who is currently using the sector dedicated band.Also, the multi-sector communication system redefines the frequencyresources of the sector dedicated band currently used by the user, asthe sector common band, so that the user continues to use the frequencyresources. Accordingly, when a user moves from a sector central regionto a cell central region, the multi-sector communication systemimmediately performs a DCA procedure to allow the user to continue touse the frequency resources of the dedicated band and allow the same tobe redefined as the sector common band in all the sectors. When thefrequency resources used by the user are occupied by other users inremaining sectors that are not yet connected with the user, themulti-sector communication system redefines the frequency resources asthe sector common band to be used by the user after allocating anotherband to the users.

Although not shown, the multi-sector communication system defines thesector common band from among the sector dedicated band, and allocatesthe same to a user who is currently using the sector dedicated band.Also, the multi-sector communication system defines different frequencyresources from the frequency resources of the sector dedicated bandcurrently used by the user, as the sector common band. In this case, thefrequency resources in use are returned as the sector dedicated bandfrom the user. Accordingly, when a user moves from a sector centralregion to a cell central region, the multi-sector communication systemimmediately performs a DCA procedure to define an empty band in commonto all the sectors, as the sector common band, allocate the same to theuser who is using the sector dedicated band, and have the sectordedicated band returned from the user. If there is no empty band incommon to all the sectors, the multi-sector communication systemallocates another frequency band to a user located in the sector centralregion or the inter-sector boundary region to prepare the empty band incommon to all the sectors, defines the frequency resources as the sectorcommon band, and allocates the same to the user.

Referring to FIG. 108, the multi-sector communication system defines thesector common band from among the inter-sector shared band and allocatesthe same to a user who is currently using the sector dedicated banddefined from among the inter-sector shared band. Also, the multi-sectorcommunication system redefines the frequency resources of the sectordedicated band defined from among the inter-sector shared band currentlyused by the user, as the sector common band, so that the user continuesto use the frequency resources. Accordingly, when a user moves from asector central region to a cell central region, the multi-sectorcommunication system immediately performs a DCA procedure to allow theuser to continue to use the frequency resources of the dedicated banddefined from among the inter-sector shared band and allow the same to beredefined as the sector common band in all the sectors. When thefrequency resources used by the user are occupied by other users inremaining sectors that are not yet connected with the user, themulti-sector communication system redefines the frequency resources asthe sector common band to be used by the user after allocating anotherband to the users.

Although not shown, the multi-sector communication system defines thesector common band from among the inter-sector shared band and allocatesthe same to a user who is currently using the sector dedicated banddefined from among the inter-sector shared band. Also, the multi-sectorcommunication system defines different frequency resources from thefrequency resources of the sector dedicated band defined from among theinter-sector shared band currently used by the user, as the sectorcommon band, so that the user uses the same. In this case, the frequencyresources in use are returned as the inter-sector shared band.Accordingly, when a user moves from a sector central region to a cellcentral region, the multi-sector communication system immediatelyperforms a DCA procedure to define an empty band in common to all thesectors, as the sector common band, allocate the same to the user who isusing the sector dedicated band defined from among the inter-sectorshared band, and have the sector dedicated band defined from among theinter-sector shared band returned from the user. If there is no emptyband in common to all the sectors, the multi-sector communication systemallocates another frequency band to a user located in the sector centralregion or the inter-sector boundary region to prepare the empty band incommon to all the sectors, defines the frequency resources as the sectorcommon band, and allocates the same to the user.

Referring to FIG. 109, the multi-sector communication system defines thesector common band and allocates the same to a user who is currentlyusing the sector dedicated band defined from among the sector commonband. Also, the multi-sector communication system redefines thefrequency resources of the sector dedicated band defined from among thesector common band currently used by the user, as the sector commonband, so that the user continues to use the frequency resources. In thiscase, the multi-sector communication system allows the sector dedicatedband defined from among the sector common band allocated to the user tobe reused as the sector dedicated band in other sectors. Accordingly,when a user moves from a sector central region to a cell central region,the multi-sector communication system immediately performs a DCAprocedure to allow the user to continue to use the frequency resourcesof the sector dedicated band defined from among the sector common bandand allow the same to be redefined as the sector common band in all thesectors. When the frequency resources used by the user are occupied byother users in remaining sectors that are not yet connected with theuser, the multi-sector communication system redefines the frequencyresources as the sector common band to be used by the user afterallocating another band to the users.

Referring to FIG. 110, the multi-sector communication system defines thesector common band and allocates the same to a user who is currentlyusing the sector dedicated band defined from among the sector commonband. Also, the multi-sector communication system redefines thefrequency resources of the sector dedicated band defined from among thesector common band currently used by the user, as the sector commonband, so that the user continues to use the frequency resources. In thiscase, the multi-sector communication system allows the sector dedicatedband defined from among the sector common band allocated to the user tobe reused as a inter-sector shared band for a inter-sector boundaryregion not adjacent to the sector where the user is located.Accordingly, when a user moves from a sector central region to a cellcentral region, the multi-sector communication system immediatelyperforms a DCA procedure to allow the user to continue to use thefrequency resources of the sector dedicated band defined from among thesector common band and allow the same to be redefined as the sectorcommon band in all the sectors. When the frequency resources used by theuser are occupied by other users in remaining sectors that are not yetconnected with the user, the multi-sector communication system redefinesthe frequency resources as the sector common band to be used by the userafter allocating another band to the users.

Although not shown, the multi-sector communication system defines thesector common band and allocates the same to a user who is currentlyusing the sector dedicated band defined from among the sector commonband. Also, the multi-sector communication system redefines differentfrequency resources from the frequency resources of the sector dedicatedband defined from among the sector common band currently used by theuser, as the sector common band, so that the user uses the same. In thiscase, the frequency resources in use are returned as the sector commonband. Accordingly, when a user moves from a sector central region to acell central region, the multi-sector communication system immediatelyperforms a DCA procedure to define an empty band in common to all thesectors, as the sector common band, allocate the same to the user who isusing the sector dedicated band defined from among the sector commonband, and have the sector dedicated band defined from among the sectorcommon band returned from the user. If there is no empty band in commonto all the sectors, the multi-sector communication system allocatesanother frequency band to a user located in the sector central region orthe inter-sector boundary region to prepare the empty band in common toall the sectors, defines the frequency resources as the sector commonband, and allocates the same to the user. An example in which DCA isperformed when a user moves from a cell central region to a sectorcentral region will be described.

FIGS. 111 to 117 illustrates an example in which DCA is performed when auser moves from a cell central region to a sector central region in amulti-sector communication system according to an exemplary embodimentof the present invention.

Referring to FIG. 111, the multi-sector communication system allocates asector dedicated band to a user who is currently using the sector commonband and has the sector common band in use returned from the user.Accordingly, when the user moves from the cell central region to thesector central region, the multi-sector communication system immediatelyperforms a DCA procedure to the user sector dedicated band to have thesector common band returned from the user. Or, when the user stays inthe sector central region for a predetermined period of time or lacksthe frequency resources of the sector common band while continuing touse the frequency resources of the sector common band, the multi-sectorcommunication system performs a DCA procedure to allocate the sectordedicated band to the user and have the sector common band in usereturned from the user.

Referring to FIG. 112, the multi-sector communication system defines thesector dedicated band from among the inter-sector shared band, allocatesthe same to a user who is currently using the sector common band, andhas the sector common band in use returned from the user. Accordingly,when the user moves from the cell central region to the sector centralregion, the multi-sector communication system immediately performs a DCAprocedure to define the sector dedicated band in the inter-sector sharedband, allocate the same to the user, and have the sector common band inuse returned from the user. Or, when the user stays in the sectorcentral region for a predetermined period of time or lacks the frequencyresources of the sector common band while continuing to use thefrequency resources of the sector common band, the multi-sectorcommunication system performs a DCA procedure to define the sectordedicated band in the inter-sector shared band, allocate the same to theuser, and have the sector common band in use returned from the user.

Referring to FIG. 113, the multi-sector communication system allocates asector dedicated band to a user that is currently using a sector commonband defined from among the inter-sector shared band, and has thefrequency resources in use returned as the inter-sector shared band.Accordingly, when the user moves from the cell central region to thesector central region, the multi-sector communication system immediatelyperforms a DCA procedure to allocate the sector dedicated band to theuser and have the sector common band defined from among the inter-sectorshared band in use returned from the user. Or, when the user stays inthe sector central region for a predetermined period of time or lacksthe frequency resources of the inter-sector shared band while continuingto use the frequency resources of the current sector common band definedfrom among the inter-sector shared band, the multi-sector communicationsystem performs a DCA procedure to allocate the sector dedicated band tothe user and have the sector common band defined from among theinter-sector shared band in use returned from the user.

Referring to FIG. 114, the multi-sector communication system allocatesthe sector dedicated band to a user who is currently using the sectorcommon band defined from among the sector dedicated band. Also, thefrequency resources of the sector common band defined from among thesector dedicated band currently used by the user are redefined as thesector dedicated band so that the user continues to use the frequencyresources. Accordingly, when the user moves from the cell central regionto the sector central region, the multi-sector communication systemimmediately performs a DCA procedure to redefine frequency resources ofthe sector common band defined from among the sector dedicated band, asthe sector dedicated band, in the sector where the user is located sothat the user continues to use the frequency resources. Or, when theuser stays in the sector central region for a predetermined period oftime or lacks the frequency resources of the sector dedicated band whilecontinuing to use the frequency resources of the sector common banddefined from among the sector dedicated band, the multi-sectorcommunication system performs a DCA procedure to redefine frequencyresources of the sector common band defined from among the sectordedicated band, as the sector dedicated band, in the sector where theuser is located, so that the user continues to use the frequencyresources.

Although not shown, the multi-sector communication system allocates thesector dedicated band to a user who is currently using the sector commonband defined from among the sector dedicated band. Also, themulti-sector communication system defines different frequency resourcesfrom the frequency resources of the sector common band defined fromamong the sector dedicated band currently used by the user, as thesector dedicated band, so that the user uses the same. In this case, themulti-sector communication system has the frequency resources in usereturned as the sector dedicated band. Accordingly, when the user movesfrom the cell central region to the sector central region, themulti-sector communication system immediately performs a DCA procedureto allocate empty frequency resources in the sector dedicated band tothe user in the sector where the user is located and have the sectorcommon band defined from among the sector dedicated band returned fromthe user. Or, when the user stays in the sector central region for apredetermined period of time or lacks the frequency resources of thesector dedicated band while continuing to use the frequency resources ofthe sector common band defined from among the sector dedicated band, themulti-sector communication system performs a DCA procedure to allocateempty frequency resources in the sector dedicated band to the user inthe sector where the user is located, and have the sector common banddefined from among the sector dedicated band in use returned from theuser.

Referring to FIG. 115, the multi-sector communication system defines thesector dedicated band from among the inter-sector shared band andallocates the same to a user that is currently using a sector commonband defined from among the inter-sector shared band. Also, themulti-sector communication system redefines frequency resources of thesector common band defined from among the inter-sector shared band thatis currently used by the user, as the sector dedicated band, so that theuser continues to use the frequency resources. Accordingly, when theuser moves from the cell central region to the sector central region,the multi-sector communication system immediately performs a DCAprocedure to redefine the sector common band defined from among thefrequency resources of the inter-sector shared band that is being usedby the user, as the sector dedicated band, in the sector where the useris located so that the user continues to use the frequency resources.When the user stays in the sector central region for a predeterminedperiod of time or lacks the frequency resources of the inter-sectorshared band while continuing to use the frequency resources of thecurrent sector common band defined from among the inter-sector sharedband, the multi-sector communication system performs a DCA procedure toredefine the sector common band defined from among the frequencyresources of the inter-sector shared band that is being used by theuser, as the sector dedicated band, in the sector where the user islocated, so that the user continues to use the frequency resources.

Although not shown, the multi-sector communication system defines thesector dedicated band from among the inter-sector shared band andallocates the same to a user that is currently using a sector commonband defined from among the inter-sector shared band. Also, themulti-sector communication system defines different frequency resourcesfrom the frequency resources of the sector common band defined fromamong the inter-sector shared band that is currently used by the user,as the sector dedicated band, so that the user uses the same. In thiscase, the frequency resources in use are returned as the inter-sectorshared band. Accordingly, when the user moves from the cell centralregion to the sector central region, the multi-sector communicationsystem immediately performs a DCA procedure to allocate empty frequencyresources in the inter-sector shared band to the user in the sectorwhere the user is located and have the sector common band defined fromamong the inter-sector shared band in use returned from the user. Or,when the user stays in the sector central region for a predeterminedperiod of time or lacks the frequency resources of the inter-sectorshared band while continuing to use frequency resources of the currentsector common band defined from among the inter-sector shared band, themulti-sector communication system performs a DCA procedure to allocateempty frequency resources in the inter-sector shared band to the user inthe sector where the user is located and have the sector common banddefined from among the inter-sector shared band returned from the user.

Referring to FIG. 116, the multi-sector communication system defines thesector dedicated band from among the sector common band and allocatesthe same to a user who is currently using the sector common band. Also,the multi-sector communication system redefines the frequency resourcesof sector common band currently used by the user, as the sectordedicated band, so that the user continues to use the frequencyresources. In this case, the multi-sector communication system allowsthe sector dedicated band defined from among the sector common bandallocated to the user to be reused as the sector dedicated band in othersectors. Accordingly, when the user moves from the cell central regionto the sector central region, the multi-sector communication systemimmediately performs a DCA procedure to redefine frequency resources ofthe sector common band, as the sector dedicated band, in the sectorwhere the user is located so that the user continues to use thefrequency resources. Or, when the user stays in the sector centralregion for a predetermined period of time or lacks the frequencyresources of the sector common band while continuing to use thefrequency resources of the sector common band, the multi-sectorcommunication system performs a DCA procedure to redefine the frequencyresources of the sector common band, as the sector dedicated band, inthe sector where the user is located, so that the user continues to usethe frequency resources.

Referring to FIG. 117, the multi-sector communication system defines thesector dedicated band from among the sector common band and allocatesthe same to a user who is currently using the sector common band. Also,the multi-sector communication system redefines the frequency resourcesof the sector common band currently used by the user, as the sectordedicated band, so that the user continues to use the frequencyresources. In this case, the multi-sector communication system allowsthe sector dedicated band defined from among the sector common bandallocated to the user to be reused as a inter-sector shared band for ainter-sector boundary region not adjacent to the sector where the useris located. Accordingly, when the user moves from the cell centralregion to the sector central region, the multi-sector communicationsystem immediately performs a DCA procedure to redefine the frequencyresources of the sector common band, as the sector dedicated band, inthe sector where the user is located so that the user continues to usethe frequency resources. Or, when the user stays in the sector centralregion for a predetermined period of time or lacks the frequencyresources of the sector common band while continuing to use thefrequency resources of the sector common band, the multi-sectorcommunication system performs a DCA procedure to redefine the frequencyresources of the sector common band, as the sector dedicated band, inthe sector where the user is located, so that the user continues to usethe frequency resources.

Although not shown, the multi-sector communication system defines thesector dedicated band from among the sector common band and allocatesthe same to a user who is currently using the sector common band. Also,the multi-sector communication system defines different frequencyresources from the frequency resources of the sector common bandcurrently used by the user as the sector dedicated band so that the useruses the same. In this case, the multi-sector communication system hasfrequency resources in use returned, as the sector common band, from theuser. Accordingly, when the user moves from the cell central region tothe sector central region, the multi-sector communication systemimmediately performs a DCA procedure to allocate empty frequencyresources in the sector common band to the user in the sector where theuser is located and have the sector common band returned from the user.Or, when the user stays in the sector central region for a predeterminedperiod of time or lacks the frequency resources of the sector commonband while continuing to use the frequency resources of the sectorcommon band, the multi-sector communication system performs a DCAprocedure to allocate empty frequency resources in the sector commonband to the user in the sector where the user is located and have thesector common band in use returned from the user.

When a load rate of the sector region exceeds a band set in each sectorregion while a user is using the divided total frequency resources inthe defined sector region, the multi-sector communication system uses anempty band. More specifically, when the load rate exceeds the set sectordedicated band due to an increase in the number of users in the sectorcentral region, the multi-sector communication system defines and usesan empty band in the inter-sector shared band or the sector common bandas the sector dedicated band. When the empty band in the inter-sectorshared band is used, the multi-sector communication system defines emptyfrequency resources in the inter-sector shared band for the sector wherethe user is located, as the sector dedicated band for the sector centralregion and allocates the same to the user. Also, when the empty band ofthe sector common band is used, the multi-sector communication systemdefines the empty frequency resources in the sector common band as thesector dedicated band for the sector central region allocates the sameto the user.

If a load rate of the inter-sector shared band is exceeded due to anincrease in users in the inter-sector boundary region, the multi-sectorcommunication system defines an empty band in the sector dedicated bandor the sector common band, as the inter-sector shared band. In thiscase, when the empty band in the sector dedicated band is used, themulti-sector communication system defines empty frequency resources incommon to the sector dedicated bands for two sectors adjacent to theinter-sector boundary region where the user is located, as theinter-sector shared band for the inter-sector boundary region, andallocates the same to the user. Here, if there are no empty frequencyresources in common to the sector dedicated bands for two sectorsadjacent to the inter-sector boundary region, the multi-sectorcommunication system allocates another frequency band to a user locatedin the sector central region to prepare an empty band in common to thesector dedicated bands for the two sectors adjacent to the inter-sectorboundary region, defines the empty band as the inter-sector shared bandfor the inter-sector boundary region, and allocates the same to theuser. Also, when the empty band of the sector common band is used, themulti-sector communication system defines the empty frequency resourcesin the sector common band as the inter-sector shared band for theinter-sector boundary region, and allocates the same to the user.

If a load rate of the sector common region shared band is exceeded dueto an increase in users in the cell central region, the multi-sectorcommunication system defines an empty band in the sector dedicated bandor the sector common band, as the sector common band. In this case, whenthe empty band in the sector dedicated band is used, the multi-sectorcommunication system defines empty frequency resources in common to thesector dedicated bands for all sectors, as the sector common band forthe cell central region, and allocates the same to the user. Here, ifthere are no empty frequency resources in common to the sector dedicatedbands for all the sectors, the multi-sector communication systemallocates another frequency band to a user located in the cell centralregion to prepare an empty band in common to the sector dedicated bandsfor all the sectors, defines the empty band as the sector common bandfor the cell central region, and allocates the same to the user. Also,when the empty band of the inter-sector shared band is used, themulti-sector communication system defines the empty frequency resourcesin all the inter-sector shared bands for all the sectors as the sectorcommon band for the cell central region, and allocates the same to theuser. If there are no empty frequency resources in common to theinter-sector shared bands for all the sectors, the multi-sectorcommunication system allocates another frequency band to a user locatedin the inter-sector boundary region to prepare the empty band in commonto the inter-sector shared bands for all the sectors, defines the emptyband as the sector common band for the cell central region, andallocates the same to the user.

While the invention has been shown and described with reference tocertain exemplary embodiments thereof, it will be understood by thoseskilled in the art that various changes in form and details may be madetherein without departing from the spirit and scope of the invention asdefined by the appended claims.

1-208. (canceled)
 209. A method for using resources in a communicationsystem, comprising: dividing a communication area into at least one ofat least one central region in which a communication node servesexclusively, at least one boundary region in which service coverages ofat least two communication nodes are overlapped and the at least twocommunication nodes serve simultaneously, and at least one common regionin which at least two communication nodes serve simultaneously; andallocating resources to at least one user terminal located in one of theat least one central region, the at least one boundary region, and theat least one common region.
 210. The method of claim 209, furthercomprising at least one of: dividing resources available to thecommunication system and allocating the divided resources as at leastone resource for the at least one central region, at least one resourcefor the at least one boundary region, and at least one resource for theat least one common region; dividing the resources available to thecommunication system and allocating the divided resources as at leastone resource for the at least one central region and at least oneresource for the at least one boundary region; dividing the resourcesavailable to the communication system and allocating the dividedresources as at least one resource for the at least one central regionand at least one resource for the at least one common region; dividingthe resources available to the communication system and allocating thedivided resources as at least one resource for the at least one boundaryregion and at least one resource for the at least one common region;dividing the resources available to the communication system andallocating the divided resources as at least one resource for the atleast one central region; allocating the resources available to thecommunication system as resources for the at least one central region;dividing the resources available to the communication system andallocating the divided resources as at least one resource for the atleast one boundary region; allocating the resources available to thecommunication system as resources for the at least one boundary region;dividing the resources available to the communication system andallocating the divided resources as at least one resource for the atleast one common region; allocating the resources available to thecommunication system as resources for the at least one common region;and allocating none of the resources available to the communicationsystem as resources for any of the at least one central region, the atleast one boundary region, and the at least one common region.
 211. Themethod of claim 210, wherein the division of resources available to thecommunication system and the allocation of the divided resources as atleast one of resources for the at least one central region, resourcesfor the at least one boundary region, and resources for the at least onecommon region comprises at least one of: allocating at least one of theresources for the at least one central region to at least one of the atleast one boundary region, the at least one common region, and at leastone another central region, for resource reuse; allocating at least oneof the resources for the at least one boundary region to at least one ofthe at least one central region, the at least one common region, and atleast one another boundary region, for resource reuse; and allocating atleast one of the resources for the at least one common region to atleast one of the at least one central region, the at least one boundaryregion, and at least one another common region, for resource reuse. 212.The method of claim 210, wherein the allocation of resources to at leastone user terminal located in one of the at least one central region, theat least one boundary region, and the at least one common regioncomprises at least one of: if a user terminal is located in one of theat least one central region, the at least one boundary region, and theat least one common region, (1) allocating available resources among theresources for the corresponding region in which the user is located, tothe user terminal; (2) changing use of available resources among theresources for the regions except for the corresponding region in whichthe user terminal is located as resources for the corresponding regionin which the user terminal is located and allocating the resources tothe user terminal; (3) designating resources that were not allocated toany of the regions as resources for the corresponding region in whichthe user terminal is located and allocating the resources to the userterminal; (4) changing use of resources in use for the user terminal asresources for the corresponding region in which the user terminal islocated and allocating the resources to the user terminal so that theuser terminal holds the resources; and (5) allocating the resources inuse for the user terminal to the user terminal without changing use ofthe resources in use for the terminal, so that the user terminal holdsthe resources.
 213. The method of claim 212, wherein each of the steps(1) to (4) comprises returning the resources in use for the userterminal by only a part of the communication nodes.
 214. The method ofclaim 212, wherein each of the steps (1) to (5) comprises allowing theuser terminal to hold the resources in use for the user terminal for afirst predetermined time and allocating the new resources to the userterminal after the first predetermined time elapses.
 215. The method ofclaim 214, wherein the allowing of the user terminal to hold theresources in use for the user terminal for a first predetermined timeand allocating resources to the user terminal after the firstpredetermined time elapses comprises allowing the user terminal to holdthe resources in use for the user terminal for a second predeterminedtime and allocating resources for a new region to the user terminalafter the second predetermined time elapses, when the user terminalmoves to the new region before the first predetermined time elapses.216. The method of claim 209, wherein the at least two communicationnodes serve simultaneously include providing no service to one userterminal by at least one of the at least two communication nodes.
 217. Amethod for using resources in a communication system, comprising:determining a communication node set including one communication node,for serving one user terminal simultaneously; and allocating in commonat least one identical resource to the user terminal by at least onecommunication node included in the communication node set.
 218. Themethod of claim 217, wherein the communication node set includes atleast one of at least one communication node that is not engaged inservice for the user terminal, at least one communication node having aservice coverage that is not adjacent to a service coverage of at leastone communication node except for the at least one communication nodeamong the communication nodes included in the communication node set, atleast one communication node having a service coverage that isoverlapped with a service coverage of at least one communication nodeexcept for the at least one communication node among the communicationnodes included in the communication node set.
 219. The method of claim217, wherein the common allocation comprises, when a new communicationnode set is created due to deletion of at least one communication nodefrom the communication node set and/or insertion of at least one newcommunication node into the communication node set, returning resourcesby communication nodes included in the communication node set andallocating in common at least one new identical resource to the userterminal by communication nodes included in the new communication nodeset.
 220. The method of claim 219, wherein the resource returning andnew resource allocation comprises one of: returning the resources by allthe communication nodes included in the communication node set;returning the resources by only a part of the communication nodesincluded in the communication node set; and holding the resourceswithout returning by any of the communication nodes included in thecommunication node set.
 221. The method of claim 217, wherein theresource returning and new resource allocation comprises at least oneof: (1) returning the resources by all the communication nodes includedin the communication node set and allocating in common the at least oneidentical resource to the user terminal by at least one of thecommunication nodes included in the new communication node set; (2)allocating in common the identical resources as resources in use for theuser terminal to the user terminal, so that the user terminal continuesto use the resources, by at least one of new communication nodesdifferent from the communication nodes included in the communicationnode set, among the communication nodes included in the newcommunication node set, if the new communication nodes can serve theuser terminal in the resources in use for the user terminal; and (3)allowing the user terminal to hold the resources in use for the userterminal without returning the resources in use for the user terminal orallocating new resources by any of the communication nodes included inthe communication node set.
 222. The method of claim 221, wherein eachof the steps (1), (2) and (3) comprises allowing the user terminal tohold the resources in use for the user terminal for a firstpredetermined time by the communication nodes included in thecommunication node set and allocating in common the at least one newidentical resource to the user terminal by at least one of thecommunication nodes included in the new communication node set, when thefirst predetermined time elapses.
 223. The method of claim 222, whereinthe allowing of the user terminal to hold the resources in use for theuser terminal for a first predetermined time by the communication nodesincluded in the communication node set and allocating in common the atleast one new identical resource to the user terminal by thecommunication nodes included in the new communication node set when thefirst predetermined time elapses comprises, when the communication nodeset is changed to a new communication node set including at least onecommunication node included in the communication node set before thefirst predetermined time elapses, allowing the user terminal to hold theresources in use for the user terminal for a second predetermined time,and allocating in common the at least one new identical resource to theuser terminal by at least one of the communication nodes included in thenew communication node set, when the second predetermined time elapses.